Very Computer

I've just had a Road Runner cable modem installed, and am trying to switch my
linux firewall server from my old ISP via diald to Road Runner via cable.

I've installed the rrlogind package from http://www.vortech.net/rrlinux, and
have the cable modem connected to eth1.  The DHCP client successfully
configures eth0, and I can ping anything on my own subnet, but whenever I try
to ping outside my subnet, I get "Network is unreachable."  Starting diald
allows me to ping ok, but that's not the way I want to go!

If I do "/sbin/route add default dev eth1", then I can see the TX LED
flashing on the cable modem, but nothing comes back.

I seem to be in a catch-22 situation.  I suspect that I can't get outside my
subnet until I've logged on to Road Runner, but the DNS'es and logon server
are all on another subnet!

Any and all suggestions gratefully accepted.  Am I missing something really
obvious here?

Thanks in advance.

Jon.

Replying to my own post, because the solution may help somebody else down the
track.

It turns out that there was nothing wrong with my linux setup.  The problem
was with the cable modem and/or Road Runner service.  I initially setup and
tested the cable modem connection using a different machine running Wintendo,
and it appears that road Runner had somehow linked the NIC ID of that machine
with the ID of the cable modem, and while it would allow another NIC to get a
DHCP connection, it would simply not pass anything outside of its own subnet
after that!

When I reconnected the original machine again, it all worked beautifully from
Windoze, OS/2 or Linux.

So the solution appears to be simply to reset the cable modem when switching
from one machine to another.  Now that I have done so, my gateway box is
working beautifully, but the original box won't work unless I reset the
modem.  Not that I need it to anymore - the linux box will remain connected
from now on.

Cheers,
  Jon.