[TriLUG] ipmasq horrors on switchover to cable modem

[Andrew Perrin]

Folks,

Any help will be appreciated.

I tried to switch over to a cable modem (earthlink, provided through Time
warner) this week.  the technician came and connected it to my wife's
windows machine ( I didn't want to scare him....).  I moved it to the
linux machine (debian woody 3.0, kernel 2.4.18) that has been happily
acting as the router for our Telocity DSL connection.

The cable modem, though, unlike telocity, uses a dynamic IP and so
requires a DHCP client. FIne, I installed dhcp3-client and tried to get
the address; I got an alert that CONFIG_PACKET and CONFIG_FILTER had to be
installed.

So, I rebuilt the kernel with those flags installed.  Tried again; now I
got a bunch of DHCPDISCOVER lines, followed by a No DHCPOFFERS received
line.

Called TWC... they told me how to reset the cable modem so it listened for
the new MAC address, but the symptom was the same.

I figured I'd give up for now and go back to telocity. Tried to... and
couldn't, I think because in the process of rebuilding the kernel I did
something terrible to my iptables setup.  But I could not figure out what
I had done wrong.  Finally, I booted to LinuxOLD, which is my old debian
potato installation, kernel 2.2.19pre17, which runs ipchains instead of
iptables.   That got me back up, and the network is at least working with
its old telocity setup.

Interestingly enough, nothing showed up in the logs to suggest packets
being swallowed by iptables in the newly-attempted setup.

Questions:
1.) Has anyone got a working earthlink cable modem setup (this uses a
Terayon TJ615 cable modem) who would be willing to send me their config
files?

2.) Can someone help me diagnose the iptables problem that killed my
network on rebuilding the kernel?  I don't even know what files to send.

Thanks for any help-
Andy Perrin

----------------------------------------------------------------------
Andrew J Perrin - http://www.unc.edu/~aperrin
Assistant Professor of Sociology, U of North Carolina, Chapel Hill
clists at perrin.socsci.unc.edu * andrew_perrin (at) unc.edu