Newbie confusion over too many DHCP server and firewalls

[Richard Treen]

My old Belkin modem/router was simple enough for me to run a nice
little home LAN. Since then I've had ISP supplied hardware, the latest
of which, had a minimal GUI.

So I got my own separate modem and router.
I'm now accessing the Internet consistently at a good speeds, so no
complaints there.

It's just that when I look into finer configurations I find it quite
confusing. Like 2 DHCP servers, each with different IP ranges?
2 different firewalls. 3 if you include Windows' own.

Is it important to have so many, or is it reasonable to turn the modem
ones off and let the router handle these things?
--

Richard Treen

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[Henry Law]

On 10/07/17 10:48, Richard Treen wrote:
> Is it important to have so many, or is it reasonable to turn the modem
> ones off and let the router handle these things?

It's certainly unnecessary (and maybe undesirable) for you to have two
DHCP servers; two firewalls doesn't sound like too bad a plan, in
principle at least.

But are you sure that your modem is what's doing it? Modems that I've
come across are just that, modems, with no other functions in.

Could you post makes, models etc for your various bits of kit?

--
Henry Law n e w s @ l a w s h o u s e . o r g
Manchester, England

[Mike Halmarack]

On Tue, 11 Jul 2017 07:26:36 +0100, Henry Law <ne...@lawshouse.org>
wrote:

>On 10/07/17 10:48, Richard Treen wrote:
>> Is it important to have so many, or is it reasonable to turn the modem
>> ones off and let the router handle these things?
>
>It's certainly unnecessary (and maybe undesirable) for you to have two
>DHCP servers; two firewalls doesn't sound like too bad a plan, in
>principle at least.
>
>But are you sure that your modem is what's doing it? Modems that I've
>come across are just that, modems, with no other functions in.
>
>Could you post makes, models etc for your various bits of kit?

The ISP provided Technicolor modem/router's Telnet config system was
daunting.
I bought a Linksys WRT1900ACS router then looked around for an ADSL2+
modem. The Draytek Vigor 130 had a reassuring name, so I got one of
those.

Later I found that there is a bit of confusion over the difference
between the "International" version of the Vigor 130, which is said to
be a Modem/Router and the UK version which is Modem only.

So, I'm less than 100% sure whether the DHCP server which is enabled
by default on the modem, is necessary for modem purposes, or is just
an obsolete artifact of the Vigor 130's modem/router version.
As you suggested, the firewall duplication might not be so
problematic.

[Henry Law]

On 11/07/17 09:27, Richard Treen (aka Mike Halmarack) wrote:
> So, I'm less than 100% sure whether the DHCP server which is enabled
> by default on the modem, is necessary for modem purposes, or is just
> an obsolete artifact of the Vigor 130's modem/router version.

I've had a quick look at the manuals and, as you say, they're really
confusing. One that I saw suggests that you can turn off the DHCP
server in the "modem"; have you tried that and if so what happens?

[Richard Treen]

On Tue, 11 Jul 2017 14:07:56 +0100, Henry Law <ne...@lawshouse.org>
wrote:

>On 11/07/17 09:27, Richard Treen (aka Mike Halmarack) wrote:
>> So, I'm less than 100% sure whether the DHCP server which is enabled
>> by default on the modem, is necessary for modem purposes, or is just
>> an obsolete artifact of the Vigor 130's modem/router version.
>
>I've had a quick look at the manuals and, as you say, they're really
>confusing. One that I saw suggests that you can turn off the DHCP
>server in the "modem"; have you tried that and if so what happens?

Thanks for looking at the manuals, I appreciate the help.
I've tried it turned off and turned on and it makes no immediate
difference to internet access quality or speed. I don't know if
there'll be other, longer term effects.

It's mainly that I have some plans to access my home system while I'm
travelling abroad and for these purposes I'm pretty sure that I'll
need more understanding and control of the hardware than I currently
have.

[Henry Law]

On 11/07/17 14:53, Richard Treen wrote:
> I've tried it turned off and turned on and it makes no immediate
> difference to internet access quality or speed. I don't know if
> there'll be other, longer term effects.

Well if internet speed is OK and your two DHCP servers aren't getting in
one another's way then I don't see that you've much to worry about right
now. I'd turn one of the DHCP servers off if I were you; if you're
bothered that the modem one is needed for something that's in there then
turn off the router one; but you say that it works OK with the modem one
turned off and that's what I'd do, personally, because it's untidy, and
untidiness in systems administration is never a good idea.

> I have some plans to access my home system while I'm
> travelling abroad

If I were you I'd think -- and plan -- extremely carefully before doing
that. For example, have a look at this:

https://superevr.com/blog/2013/dont-use-linksys-routers/

It doesn't matter if you don't have a Linksys router of this kind; the
point I'm making is that for security you're depending on code that
someone else has written, and for consumer-grade kit the manufacturers
don't always have the funds to harden their router code properly.

[Richard Treen]

On Tue, 11 Jul 2017 17:10:23 +0100, Henry Law <ne...@lawshouse.org>
wrote:

>On 11/07/17 14:53, Richard Treen wrote:
>> I've tried it turned off and turned on and it makes no immediate
>> difference to internet access quality or speed. I don't know if
>> there'll be other, longer term effects.
>
>Well if internet speed is OK and your two DHCP servers aren't getting in
>one another's way then I don't see that you've much to worry about right
>now. I'd turn one of the DHCP servers off if I were you; if you're
>bothered that the modem one is needed for something that's in there then
>turn off the router one; but you say that it works OK with the modem one
>turned off and that's what I'd do, personally, because it's untidy, and
>untidiness in systems administration is never a good idea.

Yes, that was my first concern, untidiness, because there are more
enough problems to keep me occupied already.
It seems that almost every new move, even the apparently simple ones,
brings up a batch of problems to deal with.
30 years of computing so far and still struggling with the details.

>> I have some plans to access my home system while I'm
>> travelling abroad
>
>If I were you I'd think -- and plan -- extremely carefully before doing
>that. For example, have a look at this:
>
>https://superevr.com/blog/2013/dont-use-linksys-routers/

Thanks, I read that with enough understanding to be horrified but not
quite enough to ensure future safety. So, once again my usual level of
expertise is available to deal with this one.

>It doesn't matter if you don't have a Linksys router of this kind; the
>point I'm making is that for security you're depending on code that
>someone else has written, and for consumer-grade kit the manufacturers
>don't always have the funds to harden their router code properly.

Now that Belkin has bought out Linksys the future will perhaps look
much rosier.

Maybe if I spend enough time struggling with the smaller problems the
big problems will be completely replaced by other big problems without
any intervention on my part at all.

Good job it's all such fun.