Another device using my IP address
Percy Walker
Normally my IP address is 192.168.0.2 as I am plugged into #2
connector on the switch. Now I have added a hub at this end and
plugged a new neighbor in and given her 192.168.0.3. Both my TCP/IP
and her's are set using Manually.
OK, everything works for a week. Until this morning when I get a
warning about another device on my TCP/IP Internet with the physical
address 00 03 93 96 16 58. I removed the hub at my end and still get
the message. However, if I change my IP's last digits from 0.2 to 0.4
I get a connection.
Two things were changed last night: on my computer I flashed new ROM
into my VST UltraTek ATA RAID card which is controlling two Western
Digital ide drives. And my neighbor started using a new version of
Limewire (which is not currently turned on.)
Could either of these events caused my TCP/IP to lose that IP address?
If not, what would cause this to happen. I have zapped PRAM 4 times. I
am on a G4 500DP running OS9.2.2 Airport is not connected at the
moment on any of the machines.
TIA,
Percy
Steve W. Jackson
rp...@hotmail.com (Percy Walker) wrote:
:> I am sharing a DSL line with a neighbor through his Ugate switch.
That "physical address" it's referring to is what's commonly known as a
MAC address. In theory, every device on the planet that does TCP/IP has
a unique one. Yours can be seen in Apple System Profiler. This message
*should* be saying that two devices have that same address -- which is a
problem. More than that, I'm not sure of...unless somebody's got some
MAC address cloning going on to some router or something that suddenly
isn't right any longer...
= Steve =
--
Steve W. Jackson
Montgomery, Alabama
Percy Walker
> MAC address. In theory, every device on the planet that does TCP/IP has
> a unique one. Yours can be seen in Apple System Profiler.
Is that physical address the Hardware Address listed under AppleTalk
in Sys Profiler?
>This message *should* be saying that two devices have that same
>address -- which is a problem.
Well, for whatever reason it is no longer a problem. I spent the day
installing a new AGP card and Formac monitor and after seeing your
reply I filled in the TCP/IP with the correct numbers and now it is
working. Strange though.
Thanks for your help.
Percy
Matthew Smith
You have a router between the DSL modem and the network. It may be
inside the DSL modem. A router usually includes a DHCP server for
assigning IP addresses automatically. A neighbour could have a switch or
hub at their place and connected another computer (or other device).
They may have manually assigned the same IP address as yours, or the
DHCP server may have given the computer the address. The problem went
away as the conflicting machine was probably turned off, hence no
conflict.
If you have a DHCP server you must make sure that the address you assign
are not in the range the DHCP server gives out to machines. The DHCP
does not not what has been set manually in each computer.
Since your neighbours can connect what they want, you may want to also
organise that each neighbour has a set list of manual IP addresses they
can use, if they want to connect other devices. Otherwise they can use
DHCP to obtain an IP address.
--
Matthew Smith
(to reply via email remove xxx)
Percy Walker
that I flashed new ROM into a VST card and the next morning my
particular IP number was being taken by something else. Then I
upgraded my AGP card, installing new extensions, etc. and my normal IP
number worked again. Something within my system could have been
disturbed and installing the new extensions may have righted it.
Neither of my two neighbors on the same DSL *internal network* were
home during this process. So nothing changed on their systems (in
fact, one was powered down) EXCEPT that the other system has Limewire
and, although it was asleep, could someone outside have been
downloading music using the same numbers? Pretty common numbers:
192.168.0.2
Percy
Matthew Smith <mat...@macxxx.com> wrote in message
Matthew Smith
> Matthew, thanks for replying. This is way over my head. What I know is
> that I flashed new ROM into a VST card and the next morning my
> particular IP number was being taken by something else. Then I
> upgraded my AGP card, installing new extensions, etc. and my normal IP
> number worked again. Something within my system could have been
> disturbed and installing the new extensions may have righted it.
> Neither of my two neighbors on the same DSL *internal network* were
> home during this process. So nothing changed on their systems (in
> fact, one was powered down) EXCEPT that the other system has Limewire
> and, although it was asleep, could someone outside have been
> downloading music using the same numbers? Pretty common numbers:
> 192.168.0.2
There must have been another machine on your network that was running
and had the same IP address.
I am not sure what a VST card is. If it is not a network card then it
would not have any effect on your networking. The same goes for the AGP
card.
The number range 192.168.0.1 to 192.168.0.254 is what is called a
private address range. They are used for private networks and cannot be
accessed directly from the internet. Usually there is one machine that
has a public IP address and a private IP address to connect to the
internet. This machine is called a router. Do you have a router, or is
your DSL modem a router? The router can assign IP addresses to machines
on your local network. This happens by getting the TCP/IP preferences to
configure using DHCP. You must ensure that the IP addresses you assign
to computers is not in the range of addresses the router will give out.
The router has no idea what you have assigned manually. If its number
range is 192.168.0.2 to whatever, you will have conflict if someone's
machine asks for an IP address.
That physical address that was in the message was telling you the
machine whose ethernet interface had your IP address. You could check
each machine that is connected to the network to see what its IP address
is. You can do this on a Mac running the Apple System Profiler. I am not
sure how to do it in Windows. You can then check that machines TCP/IP
settings.
If your network includes wireless then it may be that you have not
secured your network and someone else was able to connect to it. You
should secure it.
Percy Walker
router (switch) and the router has ethernet connections to one G4 and
one hub that connects to two more G4s. (I have disconnected the hub
and it is not part of this problem.) The router is available through
my browser as the IP number 192.168.0.1.
The problem suddenly occurred again tonight and we believe it ended
when we rebooted the router. Ah-ha! In checking the DHCP Clients Table
of the router it lists DHCP Hostname (blank), IP Address (same as
mine), and Mac Address as the number of the machine blocking my access
to this number, of course!
So the router is using the same IP address I want to use. But this
system has been working without incident for months now and suddenly
it is a issue. I wonder why? And why sometimes it works and other
times it stops my machine from using that IP address?
Sorry, this may seem perfectly natural to you but it is almost black
magic to me.
Thank you for your help.
Percy
Matthew Smith <mat...@macxxx.com> wrote in message
Matthew Smith
rp...@hotmail.com (Percy Walker) wrote:
> Matthew, you are correct. We have a DSL modem that connects to a
> router (switch) and the router has ethernet connections to one G4 and
> one hub that connects to two more G4s. (I have disconnected the hub
> and it is not part of this problem.) The router is available through
> my browser as the IP number 192.168.0.1.
>
> The problem suddenly occurred again tonight and we believe it ended
> when we rebooted the router. Ah-ha! In checking the DHCP Clients Table
> of the router it lists DHCP Hostname (blank), IP Address (same as
> mine), and Mac Address as the number of the machine blocking my access
> to this number, of course!
>
> So the router is using the same IP address I want to use. But this
> system has been working without incident for months now and suddenly
> it is a issue. I wonder why? And why sometimes it works and other
> times it stops my machine from using that IP address?
>
> Sorry, this may seem perfectly natural to you but it is almost black
> magic to me.
You router is giving out IP addresses which you are manually assigning
to to computers, as shown by the DHCP table. Somewhere on your network
someone as used DHCP to ask for an IP address. If you want to manually
assign that IP address you should change the number range the DHCP
server in the router uses. Change it to 192.168.0.200 to 192.168.0.220.
That should stop you from having that problem. But make sure no-one
manually assigns those addresses to a computer.
David Stone
Matthew Smith <mat...@macxxx.com> wrote:
> In article <e00f8211.0301...@posting.google.com>,
> rp...@hotmail.com (Percy Walker) wrote:
>
> > Matthew, you are correct. We have a DSL modem that connects to a
> > router (switch) and the router has ethernet connections to one G4 and
> > one hub that connects to two more G4s. (I have disconnected the hub
> > and it is not part of this problem.) The router is available through
> > my browser as the IP number 192.168.0.1.
> >
> > The problem suddenly occurred again tonight and we believe it ended
> > when we rebooted the router. Ah-ha! In checking the DHCP Clients Table
> > of the router it lists DHCP Hostname (blank), IP Address (same as
> > mine), and Mac Address as the number of the machine blocking my access
> > to this number, of course!
Does this MAC address correspond to one of your other computers at all?
If not, then someone seems to be getting free connectivity via your
router. You did change the default password on your router's setup
screens when you installed it, right? If that doesn't make any sense,
then please read your user manual now!
> > So the router is using the same IP address I want to use. But this
> > system has been working without incident for months now and suddenly
> > it is a issue. I wonder why? And why sometimes it works and other
> > times it stops my machine from using that IP address?
> >
> > Sorry, this may seem perfectly natural to you but it is almost black
> > magic to me.
>
> You router is giving out IP addresses which you are manually assigning
> to to computers, as shown by the DHCP table. Somewhere on your network
> someone as used DHCP to ask for an IP address. If you want to manually
> assign that IP address you should change the number range the DHCP
> server in the router uses. Change it to 192.168.0.200 to 192.168.0.220.
> That should stop you from having that problem. But make sure no-one
> manually assigns those addresses to a computer.
Again, you can see what range of addresses your router will hand out
from it's setup screens - read the manual!!
Percy Walker
the issue is the router is old and was pulled out to be used again
after two years. Plus it is in the other guy's house and he works 12
hour days (as a tech. dir. for an unnamed effects house). And I don't
want to walk in there and change settings around when I understand
little about what exactly is taking place inside that router.
But yes, I agree, changing the IP numbers the router gives out for us
to use with our computers would be a good step. It just seems strange
that this problem occurred after working smoothly for two months.
Eventually I will learn all about DHCP, DHCP Clients tables, and DHCP
hosts. i can hardly wait!
Percy
Robert Charles
Walker <rp...@hotmail.com> wrote:
> OK, everything works for a week.
DHCP gives out ip addresses for a period of time. I forget how long it
is, but it is in the range of hours to days. The recieving computer
must request that its ip address be renewed every so often.
Here is the thought. DHCP give out the ip address. The recieving
computer does not shutdown properly so it still has a lock on the IP
address but is not on network. I assume you could use this IP address.
Either the powered down computer comes back on the network or the time
for the IP address expires and DHCP gives it to another computer.
Keeping track of IP address manually is a pain. After awhile things
get out of control unless you get organized. You end up picking a
randomn IP address in your range and hoping it is OK. If you get a
confllict, you pick another one. Try pinging first.
The first computer to get the ip address wins. Both machines will get
the IP conflict message. Another method is lot let you machine on with
the conflicted IP address and see who complains.
The last two paragraphs are talken from acedemic settings.
Robert
Matthew Smith
willie raye <wil...@macknowledge.net> wrote:
> DHCP is useful for managing a large number of IP addresses like at a
> university campus, big office building, an ISP office, etc. IMO,
> managing IP addresses in a home environment or where there are a handful
> of devices is not a significant task and often you want IP addresses to
> stay the same. You can assign addresses manually (without duplicating
> any of them) once, record them and the task of management is done until
> you add or change something.
>
> Then you don't have to learn about DHCP. You don't even have to learn
> how or where to turn it off.
If you have a DHCP server running on your network it is advisable to
avoid manually assigning IP addresses that the server gives out. The
default network setup of a computer is to use DHCP. If you connect a
machine to the network it will get an IP address from the server, if you
have manually assigned the address to another computer you will have
conflict.
Clark Martin
> In article <e00f8211.03012...@posting.google.com>,
> rp...@hotmail.com (Percy Walker) wrote:
>
> > Eventually I will learn all about DHCP, DHCP Clients tables, and DHCP
> > hosts. i can hardly wait!
>
> DHCP is useful for managing a large number of IP addresses like at a
> university campus, big office building, an ISP office, etc. IMO,
> managing IP addresses in a home environment or where there are a handful
> of devices is not a significant task and often you want IP addresses to
> stay the same. You can assign addresses manually (without duplicating
> any of them) once, record them and the task of management is done until
> you add or change something.
>
> Then you don't have to learn about DHCP. You don't even have to learn
> how or where to turn it off.
Even in small networks DHCP is useful. It makes it easy for guest
computers to hook up. Also for laptops that are used in multiple
locations.
--
Clark Martin
Redwood City, CA, USA Macintosh / Internet Consulting
"I'm a designated driver on the Information Super Highway"