I have two machines connected in a local LAN and the newer machine also has a ethernet card through a cable modem to the internet.
When I just booted them with the CD they didn't find each other.
Here's what I did - it might help you.
Boot both machines with the ClusterKnoppix CD.
On the new machine configure the local connection first (things go wrong if the cable modem is done first). I forget the precise IP number that is used by default but call it X.Y.Z.1
I accepted that default number and all the other defaults. Then I configured the cable modem connection (as DHCP).
Then as root execute:
omdiscd -i eth0
where eth0 (or eth1 etc.) is the name of the connection.

Now on the old machine I configured its ethernet card. The default IP number is again X.Y.Z.1 and I changed it to X.Y.Z.2, accepted all the other defaults and then executed:
omdiscd -i eth0

Now they could both see each other and processes would migrate and if you save the configuration on each machine and boot up with myconfig=scan they'll come up next time without needed to be configured.
It was really cool seeing the processes migrate. In 1982 I did my M.Sc thesis on process migration and it was nowhere as easy to do then.

Best Wishes
Pete