How does setting a static IP on a mobile device prevent linux router from assigning that IP address?

[Tomos Davies]

How does setting a static IP on a linux Android mobile device prevent the
linux router from assigning that IP address to another device?

On any mobile device (iOS, Android, whatever), you can set up an FTP server
(eg ES File Explorer on Android) with a static IP address so that Windows
"My Network Places" has a permanent "shortcut" to the entire mobile device
file system (eg ftp://192.158.1.15:3721).

This is very useful, and I've been using it for a couple of weeks ever
since it was discussed here - because it effectively mounts the mobile
device as a network drive on Windows without adding any new software on
either Android or Windows.

The Android linux mobile device seems to retain the static IP address even
after multiple boots of the linux Android phone or of the Linux SOHO router
which is set up to serve DHCP addresses.

How does that work?
Why doesn't the linux router give another linux device the IP address
"192.168.1.15"?

It seems as if it works by "magic" but there must be some logic here.

How does setting the IP address to be static on the Android phone cause the
linux router to *accept* that static address permanently?





which can be set up in the mobile device connection settings
Android: Settings > WiFi > AP > Modify network config > IP settings >
static (IP address = 192.158.1.15)

[Mike Easter]

Tomos Davies wrote:
> How does setting the IP address to be static on the Android phone cause the
> linux router to *accept* that static address permanently?

It doesn't (permanently); it is still dynamic to the router.

For the same reason that when a cable modem releases its leased IP,
waits a short while, and then renews its lease with the DHCP, it gets
the exact same dyanmic IP back again. Normally.

However, you should be able to get the router to attach a particular LAN
IP to a particular MAC address device on the LAN.

--
Mike Easter

[Whiskers]

On 2017-04-11, Tomos Davies <cariad...@gmail.com> wrote:
> How does setting a static IP on a linux Android mobile device prevent the
> linux router from assigning that IP address to another device?

[...]

My guess is that your router's DHCP server originally gave your Android
device the dynamic IP number 192.168.1.15 (not 192.158.1.15 - that's a
publicly routable IP number) and still has it associated with that
device because it hasn't run out of unused IP numbers for allocating to
other devices on your LAN. That could happen easily if for example you
have six devices that connect to your LAN but the router is set to use a
range of 100 dynamic IP numbers. So when your Android device asks the
router 'can I be 192.168.1.15' then the router says 'OK'.

Dynamic IPs don't /have/ to change each time you disconnect and
reconnect.

You may be able to set the router to use a static IP for the Android
device and DHCP for everything else, if you want to be sure.

--
-- ^^^^^^^^^^
-- Whiskers
-- ~~~~~~~~~~

[Tim]

Whiskers <catwh...@operamail.com> wrote in
news:slrnoeqq4c.3...@ID-107770.user.individual.net:

> Dynamic IPs don't /have/ to change each time you disconnect and
> reconnect.
>
> You may be able to set the router to use a static IP for the Android
> device and DHCP for everything else, if you want to be sure.
>

Usually, your router is acting as a DHCP host for the rest of the devices
on your network. In the setup for DHCP on the router, there is a setting
that lets you define the range of available DHCP addresses. Just set that
range so that some of the 255 addresses are not within the range of DHCP
addresses, then pick one of those outside that range to use as your static
IP

[Kees Nuyt]

On Tue, 11 Apr 2017 22:10:39 -0000 (UTC), Tomos Davies
<cariad...@gmail.com> wrote:

> How does setting a static IP on a linux Android mobile device prevent the
> linux router from assigning that IP address to another device?

If you did it correctly, you assigned a static IP address
_outside_ the so-called DHCP range.
Any DHCP server, like in your router is set up to hand out
addresses in a specific range. Example:

network 192.168.1.0
netmask 255.255.255.0
gateway 192.168.1.1 (the address of the router on the LAN)
DHCP range 192.168.1.16 - 192.168.1.63

Now, if you decide to assign static addresses to any device, those
addresses have to be outside the DHCP range.

192.168.1.0 invalid, it is the address of the network as a whole
192.168.1.1 invalid, used by the router
192.168.1.2 valid, outside DHCP range
192.168.1.25 invalid, in the DHCP range
192.168.1.102 valid, outside DHCP range
192.168.1.255 invalid, broadcast address for this network

> On any mobile device (iOS, Android, whatever), you can set up an FTP server
> (eg ES File Explorer on Android) with a static IP address so that Windows
> "My Network Places" has a permanent "shortcut" to the entire mobile device
> file system (eg ftp://192.158.1.15:3721).

You probably mean 192.168.1.15 .

> This is very useful, and I've been using it for a couple of weeks ever
> since it was discussed here - because it effectively mounts the mobile
> device as a network drive on Windows without adding any new software on
> either Android or Windows.
>
> The Android linux mobile device seems to retain the static IP address even
> after multiple boots of the linux Android phone or of the Linux SOHO router
> which is set up to serve DHCP addresses.
>
> How does that work?
> Why doesn't the linux router give another linux device the IP address
> "192.168.1.15"?
>
> It seems as if it works by "magic" but there must be some logic here.
>
> How does setting the IP address to be static on the Android phone cause the
> linux router to *accept* that static address permanently?
>
>
> which can be set up in the mobile device connection settings
> Android: Settings > WiFi > AP > Modify network config > IP settings >
>static (IP address = 192.158.1.15)

HTH
--
Regards,
Kees Nuyt

[Carlos E.R.]

On 2017-04-12 00:10, Tomos Davies wrote:
> How does setting a static IP on a linux Android mobile device prevent the
> linux router from assigning that IP address to another device?

It doesn't.

There are three possibilities, though.

a) You accidentally assigned your phone an IP outside of the range
your router uses for DHCP addresses. Ie, the range dedicated to manually
given fixed addresses.

b) You accidentally assigned your phone the same IP as the router had
given it by DHCP.

c) You happen to have a router that before assigning an IP, first
pings that IP to see if it responds, then automatically removes that IP
from the pool of addresses it can give.



You should make sure that 'a' is true.


--
Cheers, Carlos.

[William Unruh]

On 2017-04-11, Tomos Davies <cariad...@gmail.com> wrote:

> How does setting a static IP on a linux Android mobile device prevent the
> linux router from assigning that IP address to another device?

It does not. You have been lucky, unless you go into the router to tell
it to reserve that IP address for that Mac address. dhcp will usually
reserve an IP for a mac for a little while, but there is no guarentee.
If your other machines are permanatly connected, there is no reason for
their IP addresses to change.

>
> On any mobile device (iOS, Android, whatever), you can set up an FTP server
> (eg ES File Explorer on Android) with a static IP address so that Windows
> "My Network Places" has a permanent "shortcut" to the entire mobile device
> file system (eg ftp://192.158.1.15:3721).
>
> This is very useful, and I've been using it for a couple of weeks ever
> since it was discussed here - because it effectively mounts the mobile
> device as a network drive on Windows without adding any new software on
> either Android or Windows.
>
> The Android linux mobile device seems to retain the static IP address even
> after multiple boots of the linux Android phone or of the Linux SOHO router
> which is set up to serve DHCP addresses.
>
> How does that work?
> Why doesn't the linux router give another linux device the IP address
> "192.168.1.15"?
>
> It seems as if it works by "magic" but there must be some logic here.
>
> How does setting the IP address to be static on the Android phone cause the
> linux router to *accept* that static address permanently?

It does not.

[tlvp]

On Tue, 11 Apr 2017 22:10:39 -0000 (UTC), Tomos Davies wrote:

> How does setting a static IP on a linux Android mobile device prevent the
> linux router from assigning that IP address to another device?

Each of the very few routers I've ever used has its 192.168.a.* address
range split into two halves: a lower range ( * running roughly 1-100) which
are treated as *fixed* addresses, *not* dynamically assignable; and an
upper range ( * roughly 101-253), dynamically assignable addresses. Here
the value "a" is either 0 or 1, depending on the router model/maker, and is
not variable.

It is *I* who can assign static addresses, from among the addresses in the
lower range; and it is the router who assigns the dynamic addresses, from
among the addresses in the upper range.

Addresses 192.168.a.254 and 192.168.a.255 are *not* assignable, not by me,
not by the router, as they play a fixed role already, as does 192.168.a.0 .

HTH, Stijn. Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP.

[Mark Lloyd]

On 04/11/2017 07:06 PM, Tim wrote:

[snip]

> Just set that
> range so that some of the 255 addresses are not within the range of DHCP
> addresses, then pick one of those outside that range to use as your static
> IP
>

Yes, put your static IP outside the DHCP pool.

BTW, that's "254 addresses" since both 0 and 255 (for the low octet)
can't be used. Also, the router itself will take one of these (often,
but not always, 1).

For my router, it uses 1 for itself, and the DHCP pool is 100-149. I use
addresses in the range 2-99.

--
Mark Lloyd
http://notstupid.us/

"If the Bible is telling the truth, then God is either untruthful or
incompetent. If God is truthful, then the Bible is either untruthful or
erroneous." [Rev. Donald Morgan, Atheologian]

[Mark Lloyd]

On 04/11/2017 10:45 PM, tlvp wrote:

[snip]

> Each of the very few routers I've ever used has its 192.168.a.* address
> range split into two halves: a lower range ( * running roughly 1-100) which
> are treated as *fixed* addresses, *not* dynamically assignable; and an
> upper range ( * roughly 101-253), dynamically assignable addresses. Here
> the value "a" is either 0 or 1, depending on the router model/maker, and is
> not variable.

'a' can be any number 0-255. The only one >1 I'm sure I've seen is 15.

On my router, 'a' is 1, the router's address is 192.168.1.1 and the DHCP
pool is 100-149. Addresses 2-99 and 150-254 are available. This is
changeable, although I haven't had a need to.

> It is *I* who can assign static addresses, from among the addresses in the
> lower range; and it is the router who assigns the dynamic addresses, from
> among the addresses in the upper range.
>
> Addresses 192.168.a.254 and 192.168.a.255 are *not* assignable, not by me,
> not by the router, as they play a fixed role already, as does 192.168.a.0 .

IIRC, I've used 192.168.a.254 and it worked fine. Maybe your router
itself is set to that.

> HTH, Stijn. Cheers, -- tlvp
>


--

[mike]

Google "address reservation".
You don't want a fixed IP address on a phone.
You want it in DHCP so it will work anywhere.
Tell YOUR router to reserve/assign a FIXED IP address to
the MAC address of the phone.
Best of both worlds. Fixed at home, DHCP elsewhere.

[nospam]

In article <h2mv4fgl68zu$.1e2u8ntp...@40tude.net>, tlvp

<mPiOsUcB...@att.net> wrote:

>
> > How does setting a static IP on a linux Android mobile device prevent the
> > linux router from assigning that IP address to another device?
>
> Each of the very few routers I've ever used has its 192.168.a.* address
> range split into two halves: a lower range ( * running roughly 1-100) which
> are treated as *fixed* addresses, *not* dynamically assignable; and an
> upper range ( * roughly 101-253), dynamically assignable addresses. Here
> the value "a" is either 0 or 1, depending on the router model/maker, and is
> not variable.

maybe by default it's that way, but you can change the dhcp range to
start/stop at whatever you want as well as the ip block.

> It is *I* who can assign static addresses, from among the addresses in the
> lower range; and it is the router who assigns the dynamic addresses, from
> among the addresses in the upper range.

you can assign static addresses to whatever you want, inside or outside
of any range in the router.

> Addresses 192.168.a.254 and 192.168.a.255 are *not* assignable, not by me,
> not by the router, as they play a fixed role already, as does 192.168.a.0 .

254 is.

[Carlos E.R.]

On 2017-04-12 06:43, Mark Lloyd wrote:
> On 04/11/2017 10:45 PM, tlvp wrote:


>> Addresses 192.168.a.254 and 192.168.a.255 are *not* assignable, not by
>> me,
>> not by the router, as they play a fixed role already, as does
>> 192.168.a.0 .
>
> IIRC, I've used 192.168.a.254 and it worked fine. Maybe your router
> itself is set to that.

It is 192.168.a.255 which is not usable, as it is the broadcast address.

--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-12 06:51, mike wrote:
> On 4/11/2017 3:22 PM, Mike Easter wrote:
>> Tomos Davies wrote:
>>> How does setting the IP address to be static on the Android phone
>>> cause the
>>> linux router to *accept* that static address permanently?
>>
>> It doesn't (permanently); it is still dynamic to the router.
>>
>> For the same reason that when a cable modem releases its leased IP,
>> waits a short while, and then renews its lease with the DHCP, it gets
>> the exact same dyanmic IP back again. Normally.
>>
>> However, you should be able to get the router to attach a particular LAN
>> IP to a particular MAC address device on the LAN.
>>
> Google "address reservation".
> You don't want a fixed IP address on a phone.

Not true, he does.

> You want it in DHCP so it will work anywhere.

It will work everywhere perfectly as it is.

Please remember that the setup only applies to his home WiFI. Other
WiFis get different configs.

--
Cheers, Carlos.

[nospam]

In article <u0c1sd-...@Telcontar.valinor>, Carlos E.R.

<robin_...@es.invalid> wrote:

> >>
> > Google "address reservation".
> > You don't want a fixed IP address on a phone.
>
> Not true, he does.

he might think he does, but he doesn't.

[Chris Green]

254 is often the default router IP, they're usually either 192.168.1.1
or (less often) 192.168.1.254 if using the 192.168.1 block.

--
Chris Green
·

[Carlos E.R.]

Your opinion noted.


--
Cheers, Carlos.

[nospam]

In article <0lc1sd-...@esprimo.zbmc.eu>, Chris Green <c...@isbd.net>
wrote:

> > > Addresses 192.168.a.254 and 192.168.a.255 are *not* assignable, not by me,
> > > not by the router, as they play a fixed role already, as does 192.168.a.0
> > > .
> >
> > 254 is.
>
> 254 is often the default router IP, they're usually either 192.168.1.1
> or (less often) 192.168.1.254 if using the 192.168.1 block.

depends on the router. it's easily changed to anything you want and it
doesn't need to be 192.168/16 either.

<http://www.downloads.netgear.com/files/answer_media/images/1524_image00
5.png>
<http://foxnetlab.com/images/images/2016/asus_rt-ac51u/web/asus_rt-ac51u
_web_eng_25.png>

[nospam]

In article <fpd1sd-...@Telcontar.valinor>, Carlos E.R.

<robin_...@es.invalid> wrote:

> >>>>
> >>> Google "address reservation".
> >>> You don't want a fixed IP address on a phone.
> >>
> >> Not true, he does.
> >
> > he might think he does, but he doesn't.
>
> Your opinion noted.

it's not an opinion. he should *not* have a fixed ip address on his
phone. that is only going to cause a world of problems, especially
since he doesn't understand what he's doing.

what he wants is a reserved address, which is done at the router.

[Piet]

tlvp wrote:
> Addresses 192.168.a.254 and 192.168.a.255 are *not* assignable, not by me,
> not by the router, as they play a fixed role already, as does 192.168.a.0 .

254 has no fixed role whatsoever; it can even be
pre-configured as command port address.

255 does: it's the network's broadcast address.

0 does: it's the network identifier address
(in ancient times it was a broadcast address).

-p

[Whiskers]

Setting his phone to use a static IP while connected to his home
network, would be a good idea if (when) he sets his router to use a
static IP for that device. If he wants to connect to other networks
away from home he should set his phone to use DHCP with them if that's
what they expect (which it probably is, as a general rule).

[Pascal Hambourg]

Le 12/04/2017 à 14:14, Whiskers a écrit :
>
> Setting his phone to use a static IP while connected to his home
> network, would be a good idea if (when) he sets his router to use a
> static IP for that device.

This does not make sense.
A static address for a device is set on the device, not on the router.

[Chris Green]

nospam <nos...@nospam.invalid> wrote:
> In article <0lc1sd-...@esprimo.zbmc.eu>, Chris Green <c...@isbd.net>
> wrote:
>
> > > > Addresses 192.168.a.254 and 192.168.a.255 are *not* assignable, not by me,
> > > > not by the router, as they play a fixed role already, as does 192.168.a.0
> > > > .
> > >
> > > 254 is.
> >
> > 254 is often the default router IP, they're usually either 192.168.1.1
> > or (less often) 192.168.1.254 if using the 192.168.1 block.
>
> depends on the router. it's easily changed to anything you want and it
> doesn't need to be 192.168/16 either.
>

I didn't say it wasn't easy to change, just that it is sometimes the
default router address. It can make things (a bit) difficult
sometimes if you change the router's address because if/when you have
to do a reset everything goes awry.

--
Chris Green
·

[nospam]

In article <slrnoes6hd.d...@ID-107770.user.individual.net>,

Whiskers <catwh...@operamail.com> wrote:

> >> >>> Google "address reservation". You don't want a fixed IP address
> >> >>> on a phone.
> >> >>
> >> >> Not true, he does.
> >> >
> >> > he might think he does, but he doesn't.
> >>
> >> Your opinion noted.
> >
> > it's not an opinion. he should *not* have a fixed ip address on his
> > phone. that is only going to cause a world of problems, especially
> > since he doesn't understand what he's doing.
> >
> > what he wants is a reserved address, which is done at the router.
>
> Setting his phone to use a static IP while connected to his home
> network, would be a good idea

it's a horrible idea because he'd have to change it every time he
leaves the house and back again when he returns.

that's a shitload of effort for absolutely no reason, since what he
claims to want can be done entirely automatically.

> if (when) he sets his router to use a
> static IP for that device.

there's nothing to set. the router doesn't care.

> If he wants to connect to other networks
> away from home he should set his phone to use DHCP with them if that's
> what they expect (which it probably is, as a general rule).

he should set it to dhcp and leave it that way, particularly since he
doesn't understand what he's doing and is likely going to make things
worse.

if he wants a particular ip address while at home (which can be useful
at times although very rarely for a phone), reserve that ip address at
the router. that way, the phone will work everywhere without needing to
constantly modify the network settings for every location. there won't
be any conflicts either.

he hasn't said *why* he wants this, and quite likely, there's an even
easier solution.

[mike]

If the router reserves and always assigns the same predefined IP address
to the MAC address of the phone in DHCP mode (and never to any other
device), it's always the same...works exactly like a static address when
connected to that router.
And it's all done in the router.

While you're in there, program the access point to restrict connections
to only those MAC addresses you choose.
That won't keep the hackers out, but will provide a little inhibition
to your neighbors borrowing your internet connection.

You can surely construct a situation where the router
has its DHCP server disabled, but that's a contrived/rare case.
Anybody doing that won't have any trouble dealing with the issues
that causes with phones.

[Pascal Hambourg]

Le 12/04/2017 à 16:39, mike a écrit :
> On 4/12/2017 5:28 AM, Pascal Hambourg wrote:
>> Le 12/04/2017 à 14:14, Whiskers a écrit :
>>>
>>> Setting his phone to use a static IP while connected to his home
>>> network, would be a good idea if (when) he sets his router to use a
>>> static IP for that device.
>>
>> This does not make sense.
>> A static address for a device is set on the device, not on the router.
>
> If the router reserves and always assigns the same predefined IP address
> to the MAC address of the phone in DHCP mode (and never to any other
> device), it's always the same.

It is fixed but still dynamically assigned, not static.

[mike]

I referred to it as address reservation.
It's functionally equivalent to static IP when used with the
home router.

Consider the nit picked, even though it detracts from understanding.

[Frank Slootweg]

nospam <nos...@nospam.invalid> wrote:
[...]

> he hasn't said *why* he wants this, and quite likely, there's an even
> easier solution.

He *has* said why he wants/needs this - a fixed ip address on his
phone while at home -, but as usual you spout all kind of bollocks
without even knowing what the problem is. And yes, his want/need *is* a
legitimate one.

But to be fair, your machine gun approach *has* hit the target! Bummer
for you that you don't know what the target was4s, nor which bullet hit
it!

[nospam]

In article <ocm00o...@ID-201911.user.individual.net>, Frank Slootweg

<th...@ddress.is.invalid> wrote:

> > he hasn't said *why* he wants this, and quite likely, there's an even
> > easier solution.
>
> He *has* said why he wants/needs this - a fixed ip address on his
> phone while at home

that's not a why.

he has not stated the problem he needs to solve and has demonstrated
that he knows very little about networking.

his *guess* is that a static ip is the solution without realizing all
the problems it will cause for both himself and others.

> -, but as usual you spout all kind of bollocks
> without even knowing what the problem is.

he never said what the problem is, so nobody, including you, has any
idea.

> And yes, his want/need *is* a
> legitimate one.

no it isn't.

there is no valid reason why a *phone* needs a static ip address.

[Whiskers]

To work properly, it needs to be set on both.

[Pascal Hambourg]

As nospam pointed out, the router does not care that a device has a
static address. What kind of precise setting do you think would be
needed on the router ?

[Whiskers]

On 2017-04-12, nospam <nos...@nospam.invalid> wrote:

> In article <slrnoes6hd.d...@ID-107770.user.individual.net>,
> Whiskers <catwh...@operamail.com> wrote:
>
>> >> >>> Google "address reservation". You don't want a fixed IP address
>> >> >>> on a phone.
>> >> >>
>> >> >> Not true, he does.
>> >> >
>> >> > he might think he does, but he doesn't.
>> >>
>> >> Your opinion noted.
>> >
>> > it's not an opinion. he should *not* have a fixed ip address on his
>> > phone. that is only going to cause a world of problems, especially
>> > since he doesn't understand what he's doing.
>> >
>> > what he wants is a reserved address, which is done at the router.
>>
>> Setting his phone to use a static IP while connected to his home
>> network, would be a good idea
>
> it's a horrible idea because he'd have to change it every time he
> leaves the house and back again when he returns.
>
> that's a shitload of effort for absolutely no reason, since what he
> claims to want can be done entirely automatically.

I admit that my memory could be faulty, it being some months since
setting up an Android device to access a WiFi access point it hadn't
used before, but doesn't the setting up on the phone of a new access
point give the user the choice between DHCP and static IP? Each
internet connection has its own settings on the phone, each one only
needs to be set up once (as long as you et it correct). DHCP is
probably what you get if you don't try to change it. The settings on
the phone for one network should not (I'd even go as far as MUST NOT)
have any effect on the settings for any other network.

So there would be no need to change any settings each time he goes out
or comes back home. The phone will automatically connect with any
network it already knows about, if that's the way it has been set up.

[...]

[Tomos Davies]

In <news:umrqecdmveaa58jcd...@dim53.demon.nl>, Kees Nuyt
suggested:

>> On any mobile device (iOS, Android, whatever), you can set up an FTP server
>> (eg ES File Explorer on Android) with a static IP address so that Windows
>> "My Network Places" has a permanent "shortcut" to the entire mobile device
>> file system (eg ftp://192.158.1.15:3721).
>
> You probably mean 192.168.1.15 .

Yes. My mistake. I had meant 168!
Thank you for correcting that.

Here is the actual URL: http://i.cubeupload.com/wboAp1.gif
The Windows "My Network Places" shortcut is to "ftp://192.168.1.15:3721".

Clicking on that "My Network Places" shortcut when the ES File Explorer FTP
server is running on the Android device opens up the entire Android
device's file system "as if it were mounted" on Windows.

The beauty is that this works for any Windows computer and for every user
on the Windows computer since there is no software to install on the
Windows computer.

I have multiple routers at home and multiple access points, so I was
surprised at how well this single change in Android worked, even after
numerous reboots of all the systems.

[Tomos Davies]

In <news:slrnoeqq4c.3...@ID-107770.user.individual.net>, Whiskers
suggested:

> My guess is that your router's DHCP server originally gave your Android
> device the dynamic IP number 192.168.1.15 (not 192.158.1.15 - that's a
> publicly routable IP number)

Ooooops. Thank you. Yes, I had meant "168" and not "158" (which was an
errant typo).

[Tomos Davies]

In <news:120420170839061290%nos...@nospam.invalid>, nospam suggested:

>> Setting his phone to use a static IP while connected to his home
>> network, would be a good idea
>
> it's a horrible idea because he'd have to change it every time he
> leaves the house and back again when he returns.

On Android, the IP address on the phone is set "per access point"!

Look at the original post again where the Android settings were shown:
Android: Settings > WiFi > {AP SSID} > Modify network config >
IP settings > Static > IP address = 192.168.1.15

Notice that the "static" setting is set *per access point*.
That means the "static" directive only applies for *that* access point.

There is a caveat which I'd like to ask the cognoscenti here to explain:

Interestingly, in practice, at home, since I have more than half a dozen
access points, you'd think I need to make the static setting for each
access point at home - but - in practice - so far anyway - the phone has
remained on the same IP address - even after multiple boots of the
computers, mobile devices, and router.

Why does it work so well (without me setting the phone's IP address to be
static for *all* my access points)?

[Tomos Davies]

In <news:120420170839061290%nos...@nospam.invalid>, nospam suggested:

>> Setting his phone to use a static IP while connected to his home
>> network, would be a good idea
>
> it's a horrible idea because he'd have to change it every time he
> leaves the house and back again when he returns.

On Android, the IP address on the phone is set "per access point"!

Look at the original post again where the Android settings were shown:
Android: Settings > WiFi > {AP SSID} > Modify network config >
IP settings > Static > IP address = 192.168.1.15

Notice that the "static" setting is set *per access point*.
That means the "static" directive only applies for *that* access point.

There is a caveat which I'd like to ask the cognoscenti here to explain:

http://i.cubeupload.com/wboAp1.gif

[nospam]

In article <slrnoesqif.1...@ID-107770.user.individual.net>,

Whiskers <catwh...@operamail.com> wrote:

> >>
> >> Setting his phone to use a static IP while connected to his home
> >> network, would be a good idea if (when) he sets his router to use a
> >> static IP for that device.
> >
> > This does not make sense.
> > A static address for a device is set on the device, not on the router.
>
> To work properly, it needs to be set on both.

nope. a static ip is set on the device. there's nothing to set on the
router.

if the router can route traffic from that ip, then it will work.
otherwise it won't.

a static ip has no advantages for a mobile device. only disadvantages.

*if* the phone's ip needs to be the same (which is rare), the proper
solution is a reserved dhcp address at the router (sometimes called
static dhcp which may be the source of the confusion).

[Mark Lloyd]

On 04/12/2017 07:14 AM, Whiskers wrote:

[snip]

>> what he wants is a reserved address, which is done at the router.
>
> Setting his phone to use a static IP while connected to his home
> network, would be a good idea if (when) he sets his router to use a
> static IP for that device. If he wants to connect to other networks
> away from home he should set his phone to use DHCP with them if that's
> what they expect (which it probably is, as a general rule).
>

Reserved address is what I recommend. You set the router so DHCP always
returns THAT IP to a device with THAT MAC. The device itself is set to
use DHCP.

--
Mark Lloyd
http://notstupid.us/

"Is man one of God's blunders, or is God one of man's blunders?"
[Nietzsche]

[Tomos Davies]

In <news:slrnoesrdf.1...@ID-107770.user.individual.net>, Whiskers
suggested:

> I admit that my memory could be faulty, it being some months since
> setting up an Android device to access a WiFi access point it hadn't
> used before, but doesn't the setting up on the phone of a new access
> point give the user the choice between DHCP and static IP? Each
> internet connection has its own settings on the phone, each one only
> needs to be set up once (as long as you et it correct). DHCP is
> probably what you get if you don't try to change it. The settings on
> the phone for one network should not (I'd even go as far as MUST NOT)
> have any effect on the settings for any other network.
>
> So there would be no need to change any settings each time he goes out
> or comes back home. The phone will automatically connect with any
> network it already knows about, if that's the way it has been set up.

You are correct.

The setting on Android for DHCP (default) or Static is "per access point".

So, there's no need to change it when I leave the house.

In practice, it's even better than that, in that I have more than a half
dozen access points at home on multiple routers, and, as if by magic, the
IP address hasn't changed yet, despite multiple reboots of all the devices.

So far, weeks later, the entire device file system is always conveniently
"mounted", seemingly automagically, on my Windows computer.
http://i.cubeupload.com/wboAp1.gif

I think this thread explained the "magic", some of which may have been by
chance since I didn't choose 192.168.1.15 - it was already *assigned* by
one of the routers - all I did was flip the Android settings for that
access point from "DHCP" (the default) to "Static".

[Mark Lloyd]

An "address reservation" IS set on the router, and is almost the same
thing as a static address. I find it preferable, since maintenance is
centralized. The device itself is set to "dynamic", but the DHCP server
in the router always provides the same IP to that device.

[Mark Lloyd]

On 04/12/2017 07:30 AM, Chris Green wrote:

[snip]

> I didn't say it wasn't easy to change, just that it is sometimes the
> default router address. It can make things (a bit) difficult
> sometimes if you change the router's address because if/when you have
> to do a reset everything goes awry.
>

There's usually no benefit to changing it, although I have when using 2
or more routers in series (where each needs to be using a different
network). Also, you might if you need to replace a router on an existing
network, and the new router uses a different 3rd octet (the 'y' in
192.168.y.x/24).

[Mark Lloyd]

On 04/12/2017 06:22 AM, nospam wrote:

[snip]

> depends on the router. it's easily changed to anything you want and it
> doesn't need to be 192.168/16 either.

The usual subnet for home routers is 192.168.y.0/24 , where 'y' is
different for different routers, but has to be the same for all
networked devices.

[snip]

[Mark Lloyd]

On 04/12/2017 07:39 AM, nospam wrote:

[snip]

> he hasn't said *why* he wants this, and quite likely, there's an even
> easier solution.
>

I use address reservation for (non-mobile) computers and networked
printers (*), so I can find them (from another computer) when I want to.
I'm not yet sure why I'd want to do that for a mobile device.

* - there's also ReplayTV, but you probably aren't interested.

[nospam]

In article <slrnoesrdf.1...@ID-107770.user.individual.net>,

Whiskers <catwh...@operamail.com> wrote:

> >> Setting his phone to use a static IP while connected to his home
> >> network, would be a good idea
> >
> > it's a horrible idea because he'd have to change it every time he
> > leaves the house and back again when he returns.
> >
> > that's a shitload of effort for absolutely no reason, since what he
> > claims to want can be done entirely automatically.
>
> I admit that my memory could be faulty, it being some months since
> setting up an Android device to access a WiFi access point it hadn't
> used before, but doesn't the setting up on the phone of a new access
> point give the user the choice between DHCP and static IP?

sure, but using static ip on a phone is a *really* bad idea because it
will be connecting to different networks as a matter of course. that
static ip isn't going to work across all of them and changing it each
time is crazy. it's virtually guaranteed that there will be a conflict
and that's really going to piss off the users of the other networks.

*if* you want an ip address to always be the same on a given network
(which in some cases is useful but not so much on a phone), then use
reserved dhcp.

reserved dhcp is sometimes called static dhcp, perhaps causing the
confusion. that's technically a contradiction, but it's not unusual to
see it called that.

<https://www.dd-wrt.com/wiki/index.php/Static_DHCP>

[nospam]

In article <uhuHA.565$3z4...@fx37.iad>, Mark Lloyd <n...@mail.invalid>
wrote:

>
> >> what he wants is a reserved address, which is done at the router.
> >
> > Setting his phone to use a static IP while connected to his home
> > network, would be a good idea if (when) he sets his router to use a
> > static IP for that device. If he wants to connect to other networks
> > away from home he should set his phone to use DHCP with them if that's
> > what they expect (which it probably is, as a general rule).
> >
>
> Reserved address is what I recommend. You set the router so DHCP always
> returns THAT IP to a device with THAT MAC. The device itself is set to
> use DHCP.

that's exactly what should be done.

[nospam]

In article <oclr4a$3hb$2...@news.mixmin.net>, Tomos Davies

<cariad...@gmail.com> wrote:

> >> Setting his phone to use a static IP while connected to his home
> >> network, would be a good idea
> >
> > it's a horrible idea because he'd have to change it every time he
> > leaves the house and back again when he returns.
>
> On Android, the IP address on the phone is set "per access point"!

no it isn't.

the ip address is normally set by a dhcp server, of which there should
be only one dhcp server on the subnet (with very rare exception, none
of which applies here).

> Look at the original post again where the Android settings were shown:
> Android: Settings > WiFi > {AP SSID} > Modify network config >
> IP settings > Static > IP address = 192.168.1.15
>
> Notice that the "static" setting is set *per access point*.
> That means the "static" directive only applies for *that* access point.
>
> There is a caveat which I'd like to ask the cognoscenti here to explain:
>
> Interestingly, in practice, at home, since I have more than half a dozen
> access points, you'd think I need to make the static setting for each
> access point at home - but - in practice - so far anyway - the phone has
> remained on the same IP address - even after multiple boots of the
> computers, mobile devices, and router.
>
> Why does it work so well (without me setting the phone's IP address to be
> static for *all* my access points)?

you really should learn about basic networking before you go fucking
around with static ips.

you *are* going to cause problems, and ones which you probably won't be
able to easily fix because you don't understand what you did.

anyway, your description of what you want to do is much better done
with host names, not fixed ip addresses, such as: myandroidphone.local.

[Mark Lloyd]

On 04/12/2017 09:45 AM, Pascal Hambourg wrote:

[snip]

> It is fixed but still dynamically assigned, not static.

"address reservation" is what most people say, but the first time I
heard of it was as "static DHCP".

[Mark Lloyd]

On 04/12/2017 09:57 AM, mike wrote:

[snip]

> I referred to it as address reservation.
> It's functionally equivalent to static IP when used with the
> home router.

It is. The difference is where you make the settings, and the fact that
the device automatically becomes dynamic when on a different network.

[BugHunter]

Mark Lloyd <n...@mail.invalid> schreef op Wo 12 Apr 2017 om 13:53:

"Man created God." [Me]

--
\ / http://nieuwsgroepen.tk
------------///-----------------------------
/ \ Bye, BugHunter

[nospam]

In article <nDuHA.854$Gc4...@fx23.iad>, Mark Lloyd <n...@mail.invalid>
wrote:

> > depends on the router. it's easily changed to anything you want and it
> > doesn't need to be 192.168/16 either.
>
> The usual subnet for home routers is 192.168.y.0/24 , where 'y' is
> different for different routers,

there is no usual.

0 and 1 are very common, but it's not unusual to see 2, 16 or even
10.*.*.* for defaults. i have all of those here.

> but has to be the same for all
> networked devices.

depends on the host mask and network configuration.

[nospam]

In article <VGuHA.1$lS...@fx16.iad>, Mark Lloyd <n...@mail.invalid>
wrote:

> > he hasn't said *why* he wants this, and quite likely, there's an even
> > easier solution.
>
> I use address reservation for (non-mobile) computers and networked
> printers (*), so I can find them (from another computer) when I want to.
> I'm not yet sure why I'd want to do that for a mobile device.

much easier to use dns.

[Stephen]

On Wed, 12 Apr 2017 02:54:24 +0200, "Carlos E.R."
<robin_...@es.invalid> wrote:

>On 2017-04-12 00:10, Tomos Davies wrote:
>> How does setting a static IP on a linux Android mobile device prevent the
>> linux router from assigning that IP address to another device?
>
>It doesn't.
>
>There are three possibilities, though.
>
> a) You accidentally assigned your phone an IP outside of the range
>your router uses for DHCP addresses. Ie, the range dedicated to manually
>given fixed addresses.
>
> b) You accidentally assigned your phone the same IP as the router had
>given it by DHCP.
>
> c) You happen to have a router that before assigning an IP, first
>pings that IP to see if it responds, then automatically removes that IP
>from the pool of addresses it can give.
>
D) you dont have enough devices for the router to get around to trying
to hand out the one you have used.....

FWIW most home routers seem pretty brain dead for the optional
subtleties in the DHCP server standards - several types i have used
will merrily hand out the same IP address that is in use by a device
after a reboot.

>
>
>You should make sure that 'a' is true.
Stephen Hope stephe...@xyzworld.com
Replace xyz with ntl to reply

[Frank Slootweg]

nospam <nos...@nospam.invalid> wrote:
> In article <ocm00o...@ID-201911.user.individual.net>, Frank Slootweg
> <th...@ddress.is.invalid> wrote:
>
> > > he hasn't said *why* he wants this, and quite likely, there's an even
> > > easier solution.
> >
> > He *has* said why he wants/needs this - a fixed ip address on his
> > phone while at home
>
> that's not a why.

Duh! I said "He *has* said". I.e. you said he hasn't, I say he has.

The "a fixed ip address on his phone while at home" is an elaboration
of "this", because it would be silly to talk about "this" if it isn't
clear what "this" refers to. You might want to look up the concept of
'context'.

> he has not stated the problem he needs to solve and has demonstrated
> that he knows very little about networking.

He *has* stated the problem he needs to solve. And you'd better worry
about your reading/comprehension problems than about his alleged lack of
networking knowledge.

> his *guess* is that a static ip is the solution without realizing all
> the problems it will cause for both himself and others.

There's no 'guessing' involved. A static IP *is* the solution.

> > -, but as usual you spout all kind of bollocks
> > without even knowing what the problem is.
>
> he never said what the problem is, so nobody, including you, has any
> idea.

He *has* said what the problem is. Sofar the only one having no idea
is you.

> > And yes, his want/need *is* a
> > legitimate one.
>
> no it isn't.
>
> there is no valid reason why a *phone* needs a static ip address.

In your uninformed/pig-headed opinion.

To compensate for your extreme clue-resistance, I'll give you two
clue-by-fours:

- It's common to describe a problem where?

- It's irrelevant that it's a phone. It has exactly nothing to do with
the device being a phone. He actually *first* uses the term "device"
several times, before he talks about "phone".

[nospam]

In article <ocmb9j...@ID-201911.user.individual.net>, Frank Slootweg

<th...@ddress.is.invalid> wrote:

>
> > his *guess* is that a static ip is the solution without realizing all
> > the problems it will cause for both himself and others.
>
> There's no 'guessing' involved. A static IP *is* the solution.

no it definitely is *not*. a static ip *will* cause problems, both for
him *and* others.

the solution is to use reserved dhcp, or ideally, dns and let the
router deal with the ip management.

[tlvp]

On Wed, 12 Apr 2017 14:11:23 +0200, Piet wrote:

> tlvp wrote:
>> Addresses 192.168.a.254 and 192.168.a.255 are *not* assignable, not by me,
>> not by the router, as they play a fixed role already, as does 192.168.a.0 .
>
> 254 has no fixed role whatsoever; it can even be
> pre-configured as command port address.

Please remember that I prefixed my remarks with this disclaimer:

: Each of the very few routers I've ever used has ...

In particular, each has used 192.168.1.254 as the URL for the HTML-ified
configuration page in the router itself, pretty blatantly ignoring your
"254 has no fixed role" remark :-) .

Other routers? I'm making no claims. Clear now? Thanks. Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP.

[nospam]

In article <1ugw1gfa3q9pz$.19kes6cm4jvb$.d...@40tude.net>, tlvp

<mPiOsUcB...@att.net> wrote:

> >> Addresses 192.168.a.254 and 192.168.a.255 are *not* assignable, not by me,
> >> not by the router, as they play a fixed role already, as does 192.168.a.0 .
> >
> > 254 has no fixed role whatsoever; it can even be
> > pre-configured as command port address.
>
> Please remember that I prefixed my remarks with this disclaimer:
>
> : Each of the very few routers I've ever used has ...

none of them did.

> In particular, each has used 192.168.1.254 as the URL for the HTML-ified
> configuration page in the router itself, pretty blatantly ignoring your
> "254 has no fixed role" remark :-) .

normally the default is .1, but regardless, it can be set to whatever
you want.

nothing about .254 is prohibited.

[Frank Slootweg]

You seem to think that your use of terms is some kind of standard.
Guess what, it isn't!

These terms are ambiguous, so when using them, you should explain what
*you* mean by them.

For example you say that a "static IP" is not the solution and that
one should use "Static DHCP" instead (which, as you say, is a misnomer).

But what you call "Static DHCP" is called "Static DHCP IP" (note the
addition of " IP"!) on my router.

Since "Static DHCP" is a contradiction in terms, is it so silly to say
"Static IP" when the actual setting in some router is "Static DHCP IP"?
No, of course it isn't, because it leaves out the silly contradiction in
terms. That the static IP is probably managed by the same function which
also assigns dynamic IPs is totally irrelevant.

So now we have your terms "Reserved DHCP"/"Static DHCP", which are
exactly the same as my term "Static IP", but yet you claim that your
solution is the right one and mine is the wrong one, which is a tad
strange for one and the same solution.

QED.

[Mark Lloyd]

On 04/12/2017 01:51 PM, nospam wrote:

[snip]

> reserved dhcp is sometimes called static dhcp, perhaps causing the
> confusion. that's technically a contradiction, but it's not unusual to
> see it called that.

It's a static (constant, doesn't change) IP. It's just the DHCP server,
rather than the client device, that keeps it static.

> <https://www.dd-wrt.com/wiki/index.php/Static_DHCP>

>


--
Mark Lloyd
http://notstupid.us/

"Is man one of God's blunders, or is God one of man's blunders?"

[Nietzsche].

[Mark Lloyd]

I do that too. The server (LAN only) here is called "gary.lan". In case
there's a problem with DNS, It doesn't hurt to know the IP too.

Also, I find my network printer is easier to access on a constant IP.

There's also my original problem (ReplayTV), which is how I got started
with static DHCP.

[Mark Lloyd]

On 04/12/2017 04:29 PM, Frank Slootweg wrote:

[snip]

> Since "Static DHCP" is a contradiction in terms,

Static IP served by DHCP. Doesn't sound like a contradiction.

"static DHCP" could also apply to a DHCP server that supplies ONLY
static IPs. I have used software like that before, although you probably
will NOT find it on your router.

[snip]

[nospam]

In article <ocmd81...@ID-201911.user.individual.net>, Frank Slootweg

<th...@ddress.is.invalid> wrote:

> > > > his *guess* is that a static ip is the solution without realizing all
> > > > the problems it will cause for both himself and others.
> > >
> > > There's no 'guessing' involved. A static IP *is* the solution.
> >
> > no it definitely is *not*. a static ip *will* cause problems, both for
> > him *and* others.
> >
> > the solution is to use reserved dhcp, or ideally, dns and let the
> > router deal with the ip management.
>
> You seem to think that your use of terms is some kind of standard.
> Guess what, it isn't!

guess what. the use is standard.

> These terms are ambiguous,

they are not in any way ambiguous. they are well defined networking
terms.

> so when using them, you should explain what
> *you* mean by them.

no need. they are industry standard terms.

> For example you say that a "static IP" is not the solution and that
> one should use "Static DHCP" instead (which, as you say, is a misnomer).

correct. static dhcp is the proper solution.

> But what you call "Static DHCP" is called "Static DHCP IP" (note the
> addition of " IP"!) on my router.

dhcp assigns ips, so calling it 'static dhcp ip' is redundant and
doesn't change anything.

> Since "Static DHCP" is a contradiction in terms,

technically yes, but it's commonly used and understood what is meant.

> is it so silly to say
> "Static IP" when the actual setting in some router is "Static DHCP IP"?

not only silly, but it's stupid because the term 'static ip' means
something completely different than 'static dhcp ip'.

using them interchangeably would be an incredibly bad idea.

what's silly is the term 'static d(ynamic) hcp', but many people call
it that and it has become common usage. call it reserved dhcp if you
prefer a less silly term, but expect to see static dhcp used to mean
the same thing. it's just how it is.

> No, of course it isn't, because it leaves out the silly contradiction in
> terms.

static dhcp ip still has the contradiction. just what do you think the
'd' in dhcp stands for?

> That the static IP is probably managed by the same function which
> also assigns dynamic IPs is totally irrelevant.

nope. it's very relevant.

static ip is configured on the device.
static dhcp/reserved dhcp is configured on the router, as is standard
(non-reserved) dhcp.

> So now we have your terms "Reserved DHCP"/"Static DHCP", which are
> exactly the same as my term "Static IP",

no they definitely are not the same.

you're using the term 'static ip' incorrectly. it is in no way the same
as reserved dhcp/static dhcp.

> but yet you claim that your
> solution is the right one and mine is the wrong one, which is a tad
> strange for one and the same solution.

the only thing strange is that you're insisting your incorrect usage is
valid. it isn't.

actually that's not all that strange, since you do that a lot.

[nospam]

In article <eMxHA.359$PI....@fx41.iad>, Mark Lloyd <n...@mail.invalid>
wrote:

> > Since "Static DHCP" is a contradiction in terms,
>
> Static IP served by DHCP. Doesn't sound like a contradiction.

just what do you think the 'd' in dhcp stands for? hint: dynamic.

expanding it gives: static dynamic host configuration protocol, which
is a contradiction.

> "static DHCP" could also apply to a DHCP server that supplies ONLY
> static IPs. I have used software like that before, although you probably
> will NOT find it on your router.

a static ip by definition is not handed out by a dhcp server. it's
configured on the device.

[nospam]

In article <0BxHA.1527$lS3...@fx16.iad>, Mark Lloyd <n...@mail.invalid>
wrote:

> > reserved dhcp is sometimes called static dhcp, perhaps causing the
> > confusion. that's technically a contradiction, but it's not unusual to
> > see it called that.
>
> It's a static (constant, doesn't change) IP. It's just the DHCP server,
> rather than the client device, that keeps it static.

it's dynamically assigned. it's just that the dhcp server reserves the
same one each time.

[William Unruh]

On 2017-04-12, Pascal Hambourg <pas...@plouf.fr.eu.org> wrote:
> Le 12/04/2017 à 14:14, Whiskers a écrit :
>>

>> Setting his phone to use a static IP while connected to his home

>> network, would be a good idea if (when) he sets his router to use a
>> static IP for that device.
>
> This does not make sense.
> A static address for a device is set on the device, not on the router.

Addresses using dhcp, are set by the router. And a router can be set
up to always give a certain MAC the same IP address always.
It is also possible to set an IP on the device itself, but that you had
better clear with the AP administrator, as the danger is may devices
having the same IP, especially if many of th edevices are on dhcp.

NOw with most routers as AP YOU are the administrator, so YOU had better
make sure your device does not have the same IP as something else. As
has been mentioned ad nausium here, there are many ways of doing so. As
has been stated, most routers reserve a certain address space for
dynamic IP requests. So you had better make sure that your static IP is
not one of those. Most routers also are willing to assign a specific IP
for a specific MAC if you register that MAC with the router. routers
will also router stuff for a machine which simply says it is at a
certain IP address (int he router's range) (ie the device simply assumes
an IP). So lots of things are possible.

[William Unruh]

On 2017-04-12, nospam <nos...@nospam.invalid> wrote:
> In article <ocm00o...@ID-201911.user.individual.net>, Frank Slootweg

><th...@ddress.is.invalid> wrote:
>
>> > he hasn't said *why* he wants this, and quite likely, there's an even
>> > easier solution.
>>

>> He *has* said why he wants/needs this - a fixed ip address on his
>> phone while at home
>
> that's not a why.
>

> he has not stated the problem he needs to solve and has demonstrated
> that he knows very little about networking.

I am so sorry. I know it is a terrible thing to have your memory go.
He HAS said why. He wasnts to be able toaddress his phone so he can ftp
to it, and transfer files to and from the phone using his Win computer.
As such not having to figure out what the IP address of the phone is
each time he does so is a convenience and he wants that convenience.

>
> his *guess* is that a static ip is the solution without realizing all
> the problems it will cause for both himself and others.

Having the router always give his phone the same IP is not a problem.
Having his phone assume an IP is also not a problem on his home network
is also not a problem on his home network is also not a problem if he is
careful to make sure he does not assign from the router's dynamic IP
range and that nohting else has that IP. It can be a problem if he then
takes his phone onto another network.

>
>> -, but as usual you spout all kind of bollocks
>> without even knowing what the problem is.
>
> he never said what the problem is, so nobody, including you, has any
> idea.

See above

[William Unruh]

On 2017-04-12, nospam <nos...@nospam.invalid> wrote:

> In article <eMxHA.359$PI....@fx41.iad>, Mark Lloyd <n...@mail.invalid>
> wrote:
>
>> > Since "Static DHCP" is a contradiction in terms,
>>
>> Static IP served by DHCP. Doesn't sound like a contradiction.
>
> just what do you think the 'd' in dhcp stands for? hint: dynamic.
>
> expanding it gives: static dynamic host configuration protocol, which
> is a contradiction.

No. The router does not do symantic parsing. It serves IP addresses. You
can, on most routers, tell it to serve a particular IP to a particular
MAC. That Many people call "static". It is the same IP address always.
It is also what most AP call static. Yes, DHCP is used, but he address
is static.

>
>> "static DHCP" could also apply to a DHCP server that supplies ONLY
>> static IPs. I have used software like that before, although you probably
>> will NOT find it on your router.
>
> a static ip by definition is not handed out by a dhcp server. it's
> configured on the device.

Unfortunately definitions are not cooked up by each individual but come
from common useage.

[Jeff Liebermann]

On 12 Apr 2017 21:29:13 GMT, Frank Slootweg <th...@ddress.is.invalid>
wrote:

>Since "Static DHCP" is a contradiction in terms, is it so silly to say
>"Static IP" when the actual setting in some router is "Static DHCP IP"?
>No, of course it isn't, because it leaves out the silly contradiction in
>terms. That the static IP is probably managed by the same function which
>also assigns dynamic IPs is totally irrelevant.

Sigh. I think we can all agreed that a (real) static IP LAN address
is NOT delivered by the DHCP server in the router, while a dynamic IP
LAN address is delivered by the DHCP server in the router. Any
objections so far?

Not hearing any, we have our first problem when the static IP address
is configured to be in the middle of the DHCP IP address pool. For
example, some routers assign almost the entire Class C IP address
block to DHCP, usually 192.168.1.2 through 192.168.1.254. That makes
it rather difficult for users to assign static IP's to their
computahs, servers, print servers, etc, and not have the router try to
assign the same address to some other machine. The obvious fix is to
assign a smaller chunk of the Class C IP address block (such as .100
to .199) to the DHCP address pool in the router and not use these for
static IP's, but what happens if the administrator or owner does do
this and leaves everything at the default settings? It's now the
routers job to figure out which IP addresses are being used on the
LAN. It can do this by pinging a prospective IP address, sniffing
traffic, digging though recent DHCP assignments (for dealing with
machines that randomly connect and disconnect), or looking at the ARP
table for addresses in use. There's an RFC for each of these. None
of them are deemed "required", which give router manufactures a great
opportunity to do leave them out, with predictable results.

In theory, if one sets a static IP address for some (mobile) device on
a network managed by a router, the router will be able to detect the
presence of that device, it's MAC address, and what IP address it is
using by one of the aforementioned methods. It will then not assign
in use addresses via DHCP. However, I wouldn't count on it. Just
keep the DHCP IP address pool, and the static assigned IP addresses
separate and you won't have a duplicate IP address problem.

Incidentally, a fun DHCP problem is drive-by DHCP, where a wireless
client, laptop, or smartphone literally drives past an open (no WPA
encryption password required) wireless router, which then assigns it
an IP address. Comcast "gateways" do that so they can do their
xfinitywifi thing. The problem is that unless the router is set to
expire such DHCP assignments rather quickly, the ARP table will
rapidly fill up causing the router to do "unexpected" things. ARP
table overflow is one reason that some coffee shop routers need to be
rebooted quite often.

Of course, there's a security problem with sequentially assigning IP
addresses via DHCP. Some evil hacker (like me) might be able to
predict the assigned IP address of some device as it is turned on or
wakes up. Then, the evil hacker can spoof that IP address on the
network and impersonate the device. So, there's some RFC for
randomizing the assignment of IP addresses by DHCP.

Finally, if you're not asleep from the boring lecture by now, we have
what I'll designate as "pre-assigned, pre-configured, or reserved
static DHCP". There are other names for it, but the mechanisms are
identical. It's considered static because it doesn't change. If you
don't like the term "static", you might be able to substitute
something that means "does not change". It's pre-assigned or
reserved, because the DHCP server is configured to look at the clients
MAC address, and check a list of IP and MAC address pairs, that match
the clients MAC address. If they match, then the DHCP server assigns
it a specific IP address. This is really handy if you want all your
machines and devices configured for just DHCP, without having to
configure IP addresses for the machine, netmask, default gateway, DNS
servers, static routes, etc. Another cool feature is that a machine
can be moved from the network with the pre-assigned static IP address,
plugged into another networks with a completely different router, and
still work without reconfiguration.


--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[nospam]

In article <ocmfq5$5nb$3...@dont-email.me>, William Unruh

<un...@invalid.ca> wrote:

> >> > Since "Static DHCP" is a contradiction in terms,
> >>
> >> Static IP served by DHCP. Doesn't sound like a contradiction.
> >
> > just what do you think the 'd' in dhcp stands for? hint: dynamic.
> >
> > expanding it gives: static dynamic host configuration protocol, which
> > is a contradiction.
>
> No. The router does not do symantic parsing. It serves IP addresses.

nobody said the router did semantic parsing.

*humans* do the parsing and the term 'static dynamic' is contradictory.

the router doesn't know nor care what humans calls it. the router just
moves the bits however it's configured.

> You
> can, on most routers, tell it to serve a particular IP to a particular
> MAC. That Many people call "static". It is the same IP address always.

true

> It is also what most AP call static.

not true.

> Yes, DHCP is used, but he address
> is static.

true.

> >> "static DHCP" could also apply to a DHCP server that supplies ONLY
> >> static IPs. I have used software like that before, although you probably
> >> will NOT find it on your router.
> >
> > a static ip by definition is not handed out by a dhcp server. it's
> > configured on the device.
>
> Unfortunately definitions are not cooked up by each individual but come
> from common useage.

which is what i've been saying all along.

[nospam]

In article <ocmfhd$5nb$2...@dont-email.me>, William Unruh

<un...@invalid.ca> wrote:

> >> > he hasn't said *why* he wants this, and quite likely, there's an even
> >> > easier solution.
> >>
> >> He *has* said why he wants/needs this - a fixed ip address on his
> >> phone while at home
> >
> > that's not a why.
> >
> > he has not stated the problem he needs to solve and has demonstrated
> > that he knows very little about networking.
>
> I am so sorry. I know it is a terrible thing to have your memory go.
> He HAS said why.

eventually he did, but not initially.

> He wasnts to be able toaddress his phone so he can ftp
> to it, and transfer files to and from the phone using his Win computer.
> As such not having to figure out what the IP address of the phone is
> each time he does so is a convenience and he wants that convenience.

if he was interested in convenience, he wouldn't be asking about static
ips. he'd be asking about dns so he doesn't need to remember any ips.

> > his *guess* is that a static ip is the solution without realizing all
> > the problems it will cause for both himself and others.
>
> Having the router always give his phone the same IP is not a problem.

yep. it's very easy to do with almost any router (a few don't support
reserved dhcp but not many).

> Having his phone assume an IP is also not a problem on his home network
> is also not a problem on his home network is also not a problem if he is
> careful to make sure he does not assign from the router's dynamic IP
> range and that nohting else has that IP.

it's not a problem only if he takes the time to configure it correctly
and guarantee there are no conflicts as well as always remembering to
change it when leaving the house and changing it back when returning.

that's a lot of ifs. otherwise, it's a problem.

> It can be a problem if he then
> takes his phone onto another network.

it almost certainly *will* be a problem on another network, both for
him as well as others using the network.

[Mark Lloyd]

On 04/12/2017 05:31 PM, nospam wrote:

[snip]

> a static ip by definition is not handed out by a dhcp server. it's
> configured on the device.
>

"Static is fixed, not changing.

--
Mark Lloyd
http://notstupid.us/

"The world is proof that God is a committee." [Bob Stokes]

[Mark Lloyd]

On 04/12/2017 05:31 PM, nospam wrote:

[snip]

>> It's a static (constant, doesn't change) IP. It's just the DHCP server,
>> rather than the client device, that keeps it static.
>
> it's dynamically assigned. it's just that the dhcp server reserves the
> same one each time.
>

Strange use of the word "dynamic", for something that DOESN'T change.
Possibly theres confusion between a DYNAMIC process and a STATIC value.

--
Mark Lloyd
http://notstupid.us/

[Daniel60]

On 12/04/2017 10:28 PM, Pascal Hambourg wrote:
> Le 12/04/2017 à 14:14, Whiskers a écrit :
>>
>> Setting his phone to use a static IP while connected to his home
>> network, would be a good idea if (when) he sets his router to use a
>> static IP for that device.
>
> This does not make sense.
> A static address for a device is set on the device, not on the router.

Could I suggest, by way of an example, that it is not a House that
determines its address, it is the *location* of the house on a street
that determines the house's address.

So a device is just a device, and doesn't really need an address until
it is connected to something else ... printer to computer, computer to
router, router to server, etc., etc.

Now, when we talk about Caravan or Winnebago, ..... that's something
else!! ;-)

Daniel

[Carlos E.R.]

On 2017-04-12 20:55, Mark Lloyd wrote:
> On 04/12/2017 09:57 AM, mike wrote:
>
> [snip]
>
>> I referred to it as address reservation.
>> It's functionally equivalent to static IP when used with the
>> home router.
>
> It is. The difference is where you make the settings, and the fact that
> the device automatically becomes dynamic when on a different network.

Notice that the way it is set currently it is static on his home only,
dynamic elsewhere. There is no problem whatsoever, just a matter of choice.


--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-12 14:39, nospam wrote:
> In article <slrnoes6hd.d...@ID-107770.user.individual.net>,
> Whiskers <catwh...@operamail.com> wrote:
>
>>>>>>> Google "address reservation". You don't want a fixed IP address
>>>>>>> on a phone.
>>>>>>
>>>>>> Not true, he does.
>>>>>
>>>>> he might think he does, but he doesn't.
>>>>
>>>> Your opinion noted.
>>>
>>> it's not an opinion. he should *not* have a fixed ip address on his
>>> phone. that is only going to cause a world of problems, especially
>>> since he doesn't understand what he's doing.
>>>
>>> what he wants is a reserved address, which is done at the router.

>>
>> Setting his phone to use a static IP while connected to his home
>> network, would be a good idea
>

> it's a horrible idea because he'd have to change it every time he
> leaves the house and back again when he returns.

Not at all.

--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-12 19:50, nospam wrote:
> In article <ocm00o...@ID-201911.user.individual.net>, Frank Slootweg

> <th...@ddress.is.invalid> wrote:
>
>>> he hasn't said *why* he wants this, and quite likely, there's an even
>>> easier solution.
>>
>> He *has* said why he wants/needs this - a fixed ip address on his
>> phone while at home
>
> that's not a why.
>
> he has not stated the problem he needs to solve and has demonstrated
> that he knows very little about networking.

Yes, he did say it. And it is a legitimate reason.

--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-13 02:08, William Unruh wrote:

> Having the router always give his phone the same IP is not a problem.
> Having his phone assume an IP is also not a problem on his home network
> is also not a problem on his home network is also not a problem if he is
> careful to make sure he does not assign from the router's dynamic IP
> range and that nohting else has that IP. It can be a problem if he then
> takes his phone onto another network.

Not even then, because the configuration is not generic. It applies only
to a single SSID. He connects to another AP, and it gets DHCP again.

--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-13 06:32, nospam wrote:
> In article <ocmfhd$5nb$2...@dont-email.me>, William Unruh
> <un...@invalid.ca> wrote:


>>> he has not stated the problem he needs to solve and has demonstrated
>>> that he knows very little about networking.
>>
>> I am so sorry. I know it is a terrible thing to have your memory go.
>> He HAS said why.
>
> eventually he did, but not initially.

He did, on the first post:

On any mobile device (iOS, Android, whatever), you
can set up an FTP server (eg ES File Explorer on
Android) with a static IP address so that Windows
"My Network Places" has a permanent "shortcut" to
the entire mobile device file system (eg ftp://192.158.1.15:3721).

This is very useful, and I've been using it for a couple of weeks
ever since it was discussed here - because it effectively mounts
the mobile device as a network drive on Windows without adding any
new software on either Android or Windows.

Notice the mention to "since it was discussed here". It is a reference
to another thread.

>
>> He wasnts to be able toaddress his phone so he can ftp
>> to it, and transfer files to and from the phone using his Win computer.
>> As such not having to figure out what the IP address of the phone is
>> each time he does so is a convenience and he wants that convenience.
>
> if he was interested in convenience, he wouldn't be asking about static
> ips. he'd be asking about dns so he doesn't need to remember any ips.

You are assuming he has a router with that capability. I have seen none.


--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-12 22:21, Stephen wrote:
> On Wed, 12 Apr 2017 02:54:24 +0200, "Carlos E.R."
> <robin_...@es.invalid> wrote:


>> c) You happen to have a router that before assigning an IP, first
>> pings that IP to see if it responds, then automatically removes that IP
>>from the pool of addresses it can give.


> FWIW most home routers seem pretty brain dead for the optional
> subtleties in the DHCP server standards - several types i have used
> will merrily hand out the same IP address that is in use by a device
> after a reboot.

Yes, indeed. I have not seen any home router doing that check. They may
exist, though.

--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-12 20:51, nospam wrote:
> In article <oclr4a$3hb$2...@news.mixmin.net>, Tomos Davies

> <cariad...@gmail.com> wrote:
>
>>>> Setting his phone to use a static IP while connected to his home
>>>> network, would be a good idea
>>>
>>> it's a horrible idea because he'd have to change it every time he
>>> leaves the house and back again when he returns.
>>

>> On Android, the IP address on the phone is set "per access point"!
>
> no it isn't.

Yes it is.

Look it up on your phone.

--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-12 20:19, Tomos Davies wrote:
> In <news:120420170839061290%nos...@nospam.invalid>, nospam suggested:

>
>>> Setting his phone to use a static IP while connected to his home
>>> network, would be a good idea
>>
>> it's a horrible idea because he'd have to change it every time he
>> leaves the house and back again when he returns.
>
> On Android, the IP address on the phone is set "per access point"!
>

> Look at the original post again where the Android settings were shown:
> Android: Settings > WiFi > {AP SSID} > Modify network config >
> IP settings > Static > IP address = 192.168.1.15
>
> Notice that the "static" setting is set *per access point*.
> That means the "static" directive only applies for *that* access point.
>
> There is a caveat which I'd like to ask the cognoscenti here to explain:
>
> Interestingly, in practice, at home, since I have more than half a dozen
> access points, you'd think I need to make the static setting for each
> access point at home - but - in practice - so far anyway - the phone has
> remained on the same IP address - even after multiple boots of the
> computers, mobile devices, and router.
>
> Why does it work so well (without me setting the phone's IP address to be
> static for *all* my access points)?

Because you are always connected to the same AP, or because all have the
same SSID.

You really must look at the DHCP configuration in the router. As you
have several AP, you should reserve that 192.168.1.15 address in the
router, to be assigned to your phone, by looking at its MAC.

--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-12 20:51, Mark Lloyd wrote:
> On 04/12/2017 07:39 AM, nospam wrote:
>
> [snip]

>
>> he hasn't said *why* he wants this, and quite likely, there's an even
>> easier solution.
>>
>

> I use address reservation for (non-mobile) computers and networked
> printers (*), so I can find them (from another computer) when I want to.
> I'm not yet sure why I'd want to do that for a mobile device.

Because he runs an FTP server on it, and accesses it from his home computer.

--
Cheers, Carlos.

[Dan Purgert]

nospam wrote:
> In article <slrnoes6hd.d...@ID-107770.user.individual.net>,
> Whiskers <catwh...@operamail.com> wrote:
>
>> >> >>> Google "address reservation". You don't want a fixed IP address
>> >> >>> on a phone.
>> >> >>
>> >> >> Not true, he does.
>> >> >
>> >> > he might think he does, but he doesn't.
>> >>
>> >> Your opinion noted.
>> >
>> > it's not an opinion. he should *not* have a fixed ip address on his
>> > phone. that is only going to cause a world of problems, especially
>> > since he doesn't understand what he's doing.
>> >
>> > what he wants is a reserved address, which is done at the router.
>>

>> Setting his phone to use a static IP while connected to his home
>> network, would be a good idea
>
> it's a horrible idea because he'd have to change it every time he
> leaves the house and back again when he returns.

Bear in mind that for android devices, you can set the IP address
settings on a per-SSID basis. Therefore, unless he connects to a
network with the same SSID, but a different addressing scheme, the
approach will cause him no grief.

It may not be the "best" approach, but it will work fine.

--
|_|O|_| Registered Linux user #585947
|_|_|O| Github: https://github.com/dpurgert
|O|O|O| PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281

[Whiskers]

On 2017-04-12, Tomos Davies <cariad...@gmail.com> wrote:
> In <news:120420170839061290%nos...@nospam.invalid>, nospam suggested:

[...]

> Interestingly, in practice, at home, since I have more than half a dozen
> access points, you'd think I need to make the static setting for each
> access point at home - but - in practice - so far anyway - the phone has
> remained on the same IP address - even after multiple boots of the
> computers, mobile devices, and router.
>
> Why does it work so well (without me setting the phone's IP address to be
> static for *all* my access points)?

I don't know why you'd need so many 'access points', but if the setup is
sensible then you'll have all the access points as part of one network,
with just one central router or computer taking care of the allocation
of local IP numbers to individual devices. It sounds as though that's
what you have. You can do this using common home-user Wifi
modem/routers or WiFi routers in 'bridge mode', or by using 'range
extenders'.

Re-booting a router or other computer shouldn't change the settings;
you'd need to do a 'factory re-set' to achieve that (don't do one of
those unless you really mean it!).

--
-- ^^^^^^^^^^
-- Whiskers
-- ~~~~~~~~~~

[Tomos Davies]

In <news:r1ltec5eld6m1hbfj...@4ax.com>, Jeff Liebermann
suggested:

> In theory, if one sets a static IP address for some (mobile) device on
> a network managed by a router, the router will be able to detect the
> presence of that device, it's MAC address, and what IP address it is
> using by one of the aforementioned methods. It will then not assign
> in use addresses via DHCP. However, I wouldn't count on it. Just
> keep the DHCP IP address pool, and the static assigned IP addresses
> separate and you won't have a duplicate IP address problem.

The theory seems to work, so far, in practice.
1. On the mobile device is already an FTP server (e.g., ES File Explorer).
2. On the mobile device is the native ability to set the IP address by AP.
3. On the PC is the native ability to "shortcut" that network address.

This worked perfectly (so far) in practice, even after multiple reboots of
all the involved devices (mobile devices, routers, and computers).

Tap tap done!

However ... this discussion has pointed out useful improvements:
A. I should reserve some addresses *outside* the range of the DHCP server.
B. I should use only those reserved addresses on the mobile devices.
C. And I should set *all* the home APs to that address (not just one AP).

The utter beauty has multiple advantages:
a. It's super easy to set up in seconds & requires no additional software!
b. Therefore, it works with *all* computers (even on different networks!)
c. The advantage of just "mounting" your file system on the PC is enormous!

This is how to set up the ES File Explorer FTP server:
ESFileExplorer: Settings > Network > Remote Manager > Settings >
Close on exit = yes (default)
Set FTP port = 3721 (default)
Set root directory = /sdcard (default) <== can be set to "/" if rooted
Set manage account = Anonymous (default)
Set charset = UTF-8 (default)
Create shortcut = (press to create desktop shortcut)

Tap once on Android (if not already running) and tap once on Windows (to
open the file manager) and you're done.

This is a pic of the "mount points" (what are they more properly called?)
http://i.cubeupload.com/wboAp1.gif

[nospam]

In article <qzFHA.18780$PI....@fx41.iad>, Mark Lloyd

<n...@mail.invalid> wrote:

>
> > a static ip by definition is not handed out by a dhcp server. it's
> > configured on the device.
> >
>
> "Static is fixed, not changing.

technically true, but the term 'static ip' has a specific meaning.

what is handed out by a dhcp server can't be a static ip, even if it
never changes.

[nospam]

In article <nBFHA.18781$PI....@fx41.iad>, Mark Lloyd

<n...@mail.invalid> wrote:

>
> >> It's a static (constant, doesn't change) IP. It's just the DHCP server,
> >> rather than the client device, that keeps it static.
> >
> > it's dynamically assigned. it's just that the dhcp server reserves the
> > same one each time.
> >
>
> Strange use of the word "dynamic", for something that DOESN'T change.
> Possibly theres confusion between a DYNAMIC process and a STATIC value.

the term 'static ip' has a specific meaning, and it's not handed out by
a dhcp server. the address may be the same one every time the dhcp
lease is renewed, but that doesn't make it a static ip.

[nospam]

In article <7464sd-...@Telcontar.valinor>, Carlos E.R.

<robin_...@es.invalid> wrote:

> >> I referred to it as address reservation.
> >> It's functionally equivalent to static IP when used with the
> >> home router.
> >
> > It is. The difference is where you make the settings, and the fact that
> > the device automatically becomes dynamic when on a different network.
>
> Notice that the way it is set currently it is static on his home only,
> dynamic elsewhere.

which means changing it every time he leaves/returns.

> There is no problem whatsoever, just a matter of choice.

a very bad choice.

[nospam]

In article <t364sd-...@Telcontar.valinor>, Carlos E.R.

<robin_...@es.invalid> wrote:


> >> Setting his phone to use a static IP while connected to his home
> >> network, would be a good idea
> >
> > it's a horrible idea because he'd have to change it every time he
> > leaves the house and back again when he returns.
>
> Not at all.

yes, because whatever ip address he picks, it will almost certainly
conflict with something on another network.

[nospam]

In article <0764sd-...@Telcontar.valinor>, Carlos E.R.

<robin_...@es.invalid> wrote:

> >>> he hasn't said *why* he wants this, and quite likely, there's an even
> >>> easier solution.
> >>
> >> He *has* said why he wants/needs this - a fixed ip address on his
> >> phone while at home
> >
> > that's not a why.
> >
> > he has not stated the problem he needs to solve and has demonstrated
> > that he knows very little about networking.
>
> Yes, he did say it. And it is a legitimate reason.

eventually, he did, and the reason is valid.

it's the proposed solution that's bad.

[nospam]

In article <mq64sd-...@Telcontar.valinor>, Carlos E.R.

<robin_...@es.invalid> wrote:

> >> He wasnts to be able toaddress his phone so he can ftp
> >> to it, and transfer files to and from the phone using his Win computer.
> >> As such not having to figure out what the IP address of the phone is
> >> each time he does so is a convenience and he wants that convenience.
> >
> > if he was interested in convenience, he wouldn't be asking about static
> > ips. he'd be asking about dns so he doesn't need to remember any ips.
>
> You are assuming he has a router with that capability. I have seen none.

then you haven't seen very many routers.

if the router supports dhcp server, and just about every router does,
then it's very easy to use dns rather than ip addresses.

it also doesn't need to be done in the router at all. use zeroconf,
which is entirely independent of the router.

[nospam]

In article <m074sd-...@Telcontar.valinor>, Carlos E.R.

<robin_...@es.invalid> wrote:

>
> > FWIW most home routers seem pretty brain dead for the optional
> > subtleties in the DHCP server standards - several types i have used
> > will merrily hand out the same IP address that is in use by a device
> > after a reboot.
>
> Yes, indeed. I have not seen any home router doing that check. They may
> exist, though.

they do exist and it's not that rare.

[Dan Purgert]

Stephen wrote:
>[...]

> FWIW most home routers seem pretty brain dead for the optional
> subtleties in the DHCP server standards - several types i have used
> will merrily hand out the same IP address that is in use by a device
> after a reboot.

Do you mean it'll hand out a previously-assigned address to a different
computer, or that it hands out the same IP address to a the same device
after the router is rebooted?

If the former, yeah, that's a problem due to the leases file being wiped
out. More an artifact of non-persistent storage than anything -
typically, I've only seen this kind of behavior in cheap SOHO routers
though.

If the latter, that's how DHCP is supposed to work. Both sides keep a
record of how long the lease lasts for. The DHCP server's record
includes the client's MAC address; and as long as the client requests
the IP be refreshed before the expiration date/time, the client will
receive the same IP address.

Typically the client refreshes the IP at the lease half-life (for
example, every 12 hours on a 24-hour DHCP Lease).

[Tomos Davies]

In <news:slrnoeuvhp.4...@ID-107770.user.individual.net>, Whiskers
suggested:

> I don't know why you'd need so many 'access points', but if the setup is
> sensible then you'll have all the access points as part of one network,
> with just one central router or computer taking care of the allocation
> of local IP numbers to individual devices.

The reason for the many access points is both for coverage and for
convenience.

Coverage is so that I can beam to the farthest reaches of the house, and to
the barn, and to the pool, and to the treehouse out back, etc.

Convenience is simply because I'm on WISP so I happen to have lots of
powerful radios on hand that dwarf (in ERP transmit power and receiver
sensitivity) that of a typical SOHO router.

Here is a picture of just a couple of those spare radios in the game room.
http://i.cubeupload.com/Skv6ex.gif

The range of these "wireless extenders" can be measured in miles, but only
if there are no walls or trees or homes or mountains in the way.

Some of my access points are set up on the same SSID while others use
different SSIDs, mostly dictated by the inability of the iOS equipment to
easily report the BSSID (the Android, Linux, and Windows equipment doesn't
have that limitation).

The extension router is also a spare router, set up as a bridge, as I
recall, wired to the main router (because the specific version of the spare
WRT54G doesn't allow wireless repeaters).

In summary, the network is set up for coverage and convenience.

> It sounds as though that's
> what you have. You can do this using common home-user Wifi
> modem/routers or WiFi routers in 'bridge mode', or by using 'range
> extenders'.

My radios are all capable of something like ten or fifteen kilometers
(assuming similar equipment & protocols on the other end), since they're
all spare radios from a professional WISP setup.

Where I live (Santa Cruz Mountains), there is no cable and no DSL.
There is just the wide open ether.

So we're all adept at getting our Internet from APs that are miles away.

While satellite is always possible, we're all on WISP, so most of us are
very familiar with the various antennas and radios necessary.

Over time, we've upgraded our radios from low power (just a few miles) to
higher power (up to the legal limit) for both 2.4GHz and now, 5GHz (for
noise reasons), so, fundamentally, we all have radios to spare out here.

To put all those spare radios to good use, we often attach them to our
routers as free "range extenders", where the extended range can be measured
in miles if we so desire.

In fact, when some houses have network problems (e.g., when the antenna
blows down), we have been known to set up tripods where we beam our
Internet access to the neighbor (with our small WISP's permission) from
house to house where we have successfully transmitted our signal for more
than a mile.

Since we live in mountains, this is easy, as long as the Fresnel zone is
relatively clear.

> Re-booting a router or other computer shouldn't change the settings;
> you'd need to do a 'factory re-set' to achieve that (don't do one of
> those unless you really mean it!).

Thanks for that advice on the factory reset!

It was a great thing when the manufacturers started putting the reset
button in the POE which saves us having to climb a tree or clamber on the
roof just to factory reset our radios!

[Whiskers]

On 2017-04-13, nospam <nos...@nospam.invalid> wrote:
> In article <7464sd-...@Telcontar.valinor>, Carlos E.R.
> <robin_...@es.invalid> wrote:
>
>> >> I referred to it as address reservation.
>> >> It's functionally equivalent to static IP when used with the
>> >> home router.
>> >
>> > It is. The difference is where you make the settings, and the fact that
>> > the device automatically becomes dynamic when on a different network.
>>
>> Notice that the way it is set currently it is static on his home only,
>> dynamic elsewhere.
>
> which means changing it every time he leaves/returns.

Why? He only needs to set the static IP for his home network, not for
any others. Once set, each network will be recognised automatically by
his phone and use the settings created specifically for it (which in
most cases will be to accept DHCP).

>> There is no problem whatsoever, just a matter of choice.
>
> a very bad choice.

A sensible choice, incompletely implemented.

[nospam]

In article <slrnoevd0n.1...@ID-107770.user.individual.net>,

Whiskers <catwh...@operamail.com> wrote:

> >> >> I referred to it as address reservation.
> >> >> It's functionally equivalent to static IP when used with the
> >> >> home router.
> >> >
> >> > It is. The difference is where you make the settings, and the fact that
> >> > the device automatically becomes dynamic when on a different network.
> >>
> >> Notice that the way it is set currently it is static on his home only,
> >> dynamic elsewhere.
> >
> > which means changing it every time he leaves/returns.
>
> Why? He only needs to set the static IP for his home network, not for
> any others. Once set, each network will be recognised automatically by
> his phone and use the settings created specifically for it (which in
> most cases will be to accept DHCP).

except when it doesn't.

> >> There is no problem whatsoever, just a matter of choice.
> >
> > a very bad choice.
>
> A sensible choice, incompletely implemented.

horrible choice.

the solution is simple: dns and let the router handle ip management,
which is what it's designed to do. alternately, reserved dhcp.

[Carlos E.R.]

On 2017-04-13 17:16, nospam wrote:
> In article <7464sd-...@Telcontar.valinor>, Carlos E.R.
> <robin_...@es.invalid> wrote:
>
>>>> I referred to it as address reservation.
>>>> It's functionally equivalent to static IP when used with the
>>>> home router.
>>>
>>> It is. The difference is where you make the settings, and the fact that
>>> the device automatically becomes dynamic when on a different network.
>>
>> Notice that the way it is set currently it is static on his home only,
>> dynamic elsewhere.
>
> which means changing it every time he leaves/returns.

He doesn't have to change anything. Just move and continue using the
phone normally.

--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-13 19:29, nospam wrote:
> In article <slrnoevd0n.1...@ID-107770.user.individual.net>,
> Whiskers <catwh...@operamail.com> wrote:
>
>>>>>> I referred to it as address reservation.
>>>>>> It's functionally equivalent to static IP when used with the
>>>>>> home router.
>>>>>
>>>>> It is. The difference is where you make the settings, and the fact that
>>>>> the device automatically becomes dynamic when on a different network.
>>>>
>>>> Notice that the way it is set currently it is static on his home only,
>>>> dynamic elsewhere.
>>>
>>> which means changing it every time he leaves/returns.
>>
>> Why? He only needs to set the static IP for his home network, not for
>> any others. Once set, each network will be recognised automatically by
>> his phone and use the settings created specifically for it (which in
>> most cases will be to accept DHCP).
>
> except when it doesn't.

Your wrong opinion noted.

--
Cheers, Carlos.

[Carlos E.R.]

On 2017-04-13 16:19, Tomos Davies wrote:

> Tap tap done!
>
> However ... this discussion has pointed out useful improvements:
> A. I should reserve some addresses *outside* the range of the DHCP server.
> B. I should use only those reserved addresses on the mobile devices.
> C. And I should set *all* the home APs to that address (not just one AP).

The setting is done only on the router, not the APs.

On the phone, you have to do the setting for all your home SSIDs. In
that case, it is easier to assign an IP on the router instead than on
the phone. A single point of configuration.

--
Cheers, Carlos.

[Whiskers]

On 2017-04-13, nospam <nos...@nospam.invalid> wrote:

> In article <slrnoevd0n.1...@ID-107770.user.individual.net>,
> Whiskers <catwh...@operamail.com> wrote:
>
>> >> >> I referred to it as address reservation.
>> >> >> It's functionally equivalent to static IP when used with the
>> >> >> home router.
>> >> >
>> >> > It is. The difference is where you make the settings, and the fact that
>> >> > the device automatically becomes dynamic when on a different network.
>> >>
>> >> Notice that the way it is set currently it is static on his home only,
>> >> dynamic elsewhere.
>> >
>> > which means changing it every time he leaves/returns.
>>
>> Why? He only needs to set the static IP for his home network, not for
>> any others. Once set, each network will be recognised automatically by
>> his phone and use the settings created specifically for it (which in
>> most cases will be to accept DHCP).
>
> except when it doesn't.

You have a device that allows settings for one access point to influence
the settings for any or all other access points? It's faulty.

>> >> There is no problem whatsoever, just a matter of choice.
>> >
>> > a very bad choice.
>>
>> A sensible choice, incompletely implemented.
>
> horrible choice.
>
> the solution is simple: dns and let the router handle ip management,
> which is what it's designed to do. alternately, reserved dhcp.

I agree that the router should allocate the unchanging IP number the
user wants it to allocate. There is no reason not to set that same IP
number on the device as well, in its settings for that network. Relying
on the router accepting a static IP number offered by the device,
without setting the router to match, could lead to problems eventually
if the user's luck runs out.

[Carlos E.R.]

On 2017-04-13 17:16, nospam wrote:

> In article <mq64sd-...@Telcontar.valinor>, Carlos E.R.
> <robin_...@es.invalid> wrote:
>
>>>> He wasnts to be able toaddress his phone so he can ftp
>>>> to it, and transfer files to and from the phone using his Win computer.
>>>> As such not having to figure out what the IP address of the phone is
>>>> each time he does so is a convenience and he wants that convenience.
>>>
>>> if he was interested in convenience, he wouldn't be asking about static
>>> ips. he'd be asking about dns so he doesn't need to remember any ips.
>>
>> You are assuming he has a router with that capability. I have seen none.
>
> then you haven't seen very many routers.
>
> if the router supports dhcp server, and just about every router does,
> then it's very easy to use dns rather than ip addresses.

All the home routers I have used have DHCP capabilities, none have
configurable DNS capabilities.

> it also doesn't need to be done in the router at all. use zeroconf,
> which is entirely independent of the router.

which doesn't always work.

I get names such as "android-c2653....", and ping from the computer does
not work.

--
Cheers, Carlos.