What configuring have you done? The very least that you will need is to make sure that ethernet (green blob) rather than internal modem (red blob) is selected in System Preferences/Network/Network Status on the iBooks. DHCP you seem to have taken care of, but what IP address is reported? You may very well be getting one of the 'I am talking to myself' addresses (169.254.x.x) if modem is selected when you need ethernet.
If ethernet is selected correctly, but still not active, you are faced with the possibility that your iBooks have borked ethernet controllers. Two at once seems unlikely, but this may depend on your sources of the Macs.
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PS What kind of Cat 5e cable are you using? If your iBooks don't 'do' auto-MDIX (iBook and iBook FireWire), you will need a crossover rather than a patch cable for direct connection to your modem. An intervening 100Base-T switch ('router') would do this automatically for you.
If ethernet is selected correctly, but still not active, you are faced with the possibility that your iBooks have borked ethernet controllers. Two at once seems unlikely, but this may depend on your sources of the Macs.
de
PS What kind of Cat 5e cable are you using? If your iBooks don't 'do' auto-MDIX (iBook and iBook FireWire), you will need a crossover rather than a patch cable for direct connection to your modem. An intervening 100Base-T switch ('router') would do this automatically for you.