two routers question

[David Bandel]

On 1/15/06, Ian Stephen <ianstepn at shaw.ca> wrote:
> A question for those who know networking
>
> I recently got VOIP (Vonage) at home, but I like the firewall in my old
> router so wanted to have
>
> - cable modem connected to VOIP router
> - telephones connected to VOIP router
> - old router connected to VOIP router
> - computers connected to old router
>
> Everything I found on the web said to disable DHCP in the second router
> and plug the cable from the VOIP router into a regular port, not the wan
> port, on the second router to make this setup work.
>
> I wanted DHCP enabled in the old router because I'm guessing it needs
> DHCP enabled for its firewall to work.  It seemed to me that the second
> router wouldn't know the difference between being connected to the cable
> modem and being connected to the VOIP router, so I just went ahead and
> plugged everything in that way.
>
> VOIP router has DHCP enabled using addresses in a range of
> 192.168.15.xxx.
>
> Old router has DHCP enabled using addresses in a range of 192.168.2.xxx.
>
> It all seems to work fine.  Was the advice I found via Google wrong or
> have I done something wrong that I just haven't noticed yet?
>

Nothing wrong with what you've done.  The advice you found would have
made your old router nothing more than a switch (not what you wanted).
 I suspect you'd find the VoIP nat/router is a good enough firewall,
but it doesn't hurt including the old router if you're more
comfortable.

These routers (your old router and the VoIP router) are nat routers. 
The interface marked "WAN" is telling you the system expects that to
be the Internet (and will accept either a static IP or will be a dhcp
client) and the other port(s) marked "LAN" will have a static IP and
act as a DHCP server.  Again, if you have various "LAN" ports, they
could just be used as a switch.  Your pleasure.

Ciao,

David A. Bandel
--
Focus on the dream, not the competition.
            - Nemesis Air Racing Team motto