Dual Home (?) ?

[kentborg at borg.org (Kent Borg)]

I don't know if "dual homing" is the accurate term here, but it's
close enough for others to use it that way...

As those of you know who have been following my saga, I am in the
midst of seeing if I can (and want) to switch my home DSL to Covad.
And, I am learning more stuff.

Yesterday I got home and plugged in my new DSL modem/router, and after
giving up on the web based wizard working with Mozilla, I figured out
how to set up the PPPoE username and password via the router's telnet
interface.  Cool!  I have a second internet line.  But I want to
figure out how to do a smooth cutover, and the first step is to get my
RH 7.0 server on both wires at the same time.

In the server I put an extra ethernet card I had kicking around, and
after futzing with some network related configuration files and the
GUI, I managed to get it kinda on both wires at once.

My problem, however, is that I can't get it to answer connections from
the new Covad connection.  I can talk to it on that ethernet card from
my notebook just fine, but connections through the Covad router to the
server don't work-- but they work just fine to the notebook.  (I have
to change the router configuration to switch between the two, but I
know how to do that.)

When trying to connect from the outside I can run a tcpdump on my
server and see the connection trying to happen and packets supposedly
being sent back.

Here are some clues.  First, is this sensible for my server:

  [root at borg root]# route -n
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  192.168.100.0   0.0.0.0         255.255.255.0   U     0      0        0 eth0
  192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 eth1
  127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo
  0.0.0.0         192.168.100.1   0.0.0.0         UG    0      0        0 eth0
  [root at borg root]# 

That looks to me like all outbound packets might go out the old eth0
connection, or will it correctly answer in the direction a connection
attempt comes from?

And a traceroute from the outside (a coworker's RH box, also on
Covad):

  $ /usr/sbin/traceroute 64.105.205.123
  traceroute to 64.105.205.123 (64.105.205.123), 30 hops max, 38 byte packets
   1  192.168.1.1 (192.168.1.1)  1.387 ms  0.897 ms  0.781 ms
   2  h-66-166-225-1.CMBRMAOR.covad.net (66.166.225.1)  12.701 ms  22.114 ms  11.313 ms
   3  * * *
   4  borg (208.218.135.231)  31.349 ms  29.858 ms  29.501 ms

Note that though I asked to trace to my new Covad static IP
(64.105.205.123), the last line mentions my Galaxy DSL static IP
(208.218.135.231)!  

How did that happen?  My computer doesn't really know anything about
208.218.135.231, that number is on the outside, I see everything
locally as 192.168.something.  Is it just the tracing computer somehow
being told it has reached borg.org and it does its own reverse lookup?

Any suggestions for how to sit happily on two wires at once?


Thanks,

-kb, the Kent who might put a dumb hub on the Covad connection next so
he can sniff packets with his noetbook.