None of my iBooks have ever had a truly bad Ethernet system, but my original BlueBerry iBook has the little retainer tab broken off of the jack, so I must be certain that the connector is stuffed in there all the way, and the thing really can't be moved once it's in place, or it'll lose the connection even though it's still kinda plugged in. Maybe that's your problem?
Quick and easy ways to determine a hardware issue:
*Are you using a hub/switch? If so, one of the lights should illuminate when the iBook is connected.
*Check the Network Utility (in OS X). It should report all of the happy details of every networking subsystem available to your computer. The wired Ethernet would be "Network Interface (en0)" in the drop-down box in the "Info" tab.
If both of the above are in the negative (or unavailable), try checking software. Sometimes people disable stuff in System Preferences (in X) or choose a different AppleTalk port (in 9). Also, check for the proper kexts/extensions or control panels.
Last resort: boot from CD/FireWire and see if it works.
Quick and easy ways to determine a hardware issue:
*Are you using a hub/switch? If so, one of the lights should illuminate when the iBook is connected.
*Check the Network Utility (in OS X). It should report all of the happy details of every networking subsystem available to your computer. The wired Ethernet would be "Network Interface (en0)" in the drop-down box in the "Info" tab.
If both of the above are in the negative (or unavailable), try checking software. Sometimes people disable stuff in System Preferences (in X) or choose a different AppleTalk port (in 9). Also, check for the proper kexts/extensions or control panels.
Last resort: boot from CD/FireWire and see if it works.