I have two Xubuntu Jaunty pc's and I want to connect them for file transfer. I have samba and pyneighborhood installed. I can't make it work.

Lan cable and connection, I believe is not the culprit as I can connect to internet If used as a standalone workstation.

How did you hook up both the pcs? to a hub?switch? Start checking from layer1 that is physical layer,check if the cable is properly plugged or not,run the command mii-tool to see if there is physical layer connectivity as such,if not then do a ifconfig -a or may ping\traceroute,more info on this would be helpful.

If you have the LAN cable going straight from one machine to the other...

You would need a cross-over cable, and each machine would need a static IP address in the same sub-net (assuming one of the machines is not acting as a DHCP server).

Basically this is what I want to do. I disconnected the cable from one of my pc,s and insert it to the lan port of the other. But I can't connect.

Can you please expound on this.

The cable wiring is different. There are eight wires in a LAN cable (although only four of these are actually used). Two wires are for sending signals and two wires are for receiving signals.

Most network cables are straight connections which are used to connect a computer to a switch or a router.

The computer is expecting signals on one set of wires and the switch or router is expecting signals on another set of wires.

When you connect two computers directly together with a normal network cable the computers are both trying to send on the same wires and are therefore getting lots of traffic on the sending wires and not getting anything on the receiving wires.

You need a different type of cable to get two PC's to talk to each other (referred to as a cross-over cable). Basically the sending and receiving wires are crossed at one end.

EDIT:-

All eight wires are used if using a gigabit network.

http://www.ertyu.org/steven_nikkel/ethernetcables.html