Sorry about the length of this, but it's a weird one... Here's my setup: AMX-64 ADSL router with four ports: - eMac connected to the router by Ethernet cable - iBook connected to router by Ethernet cable - PBook connected via Airport Express which in turn is connected to the router by Ethernet Up until today I have had no problems with any of these connections. Today I finally got around to downloading and installing various security updates, the Java update and the latest QuickTime update on to the eMac. I initially had a few problems with the router and couldn't connect to the download site, but this was sorted out with a quick router restart and the downloads went smoothly and the software was installed with no problem. I have made no changes to the iBook and PB. My daughter has the iBook in her bedroom and some time after the eMac installs she complained that she was unable to connect to the 'net - she constantly got the Safari error message that Safari couldn't find the relevant server for any site. We tried IE but got the same sort of result: unable to find the server. The eMac was still able to connect so I suspected the iBooks Ethernet cable was broken. I took the iBook downstairs and plugged the cable from the eMac into the iBook and got the same unable to find server error message when I tried to connect. I plugged the same cable back into the eMac and connected straight away (in each case I tried to connect to uk.yahoo.com). Thinking the Ethernet port on the iBook was damaged I re-connected the cable and opened System Preferences > Network to find that an IP address had been assigned, implying that the Ethernet port was working. I woke up the PB, turned on the Airport, got a good signal and tried to connect to uk.yahoo.com and that gave me the unable to find server message. I plugged the eMacs Ethernet cable (which I know is working) into the PB, checked that it had been assigned an IP address, and tried to connect to uk.yahoo.com and it again failed to find the server. Next I moved the good Ethernet cable back to the iBook and tried to connect the PB to the iBook (which was still connected through the eMacs cable) and it worked, which could only mean that: - the PB was connecting to the router properly via the Aiport Express/Ethernet cable; - the iBook was connecting to the router via the eMacs Ethernet cable, so the iBooks Ethernet port was definitely working. I disconnected the two laptops then reconnected the eMac to the router with its normal cable, and succesfully connected the PB to the eMac. So ... by a process of elimination I have concluded that all my hardware is working correctly: 1) the Ethernet port on the iBook is working as expected; 2) the router is getting out to the net, as the eMac has no problem connecting (I'm typing on the eMac now); 3) the eMacs Ethernet cable is good; 4) the PBs Airport and the Airport Express are working correctly, and the AEx can connect to the router. I opened Network Utility on the PB and tried to ping the router itself - strangely enough this failed with the messages: ping:sendto:No route to host PING 10.0.0.2 (10.0.0.2):56 data bytes ping:wrote 10.0.0.2 64 chars, ret=-1 --- 10.0.0.2 ping statistics --- 1 packets transmitted, 0 packets received, 100% packet loss I also tried to ping www.apple.com and immediately got the response ping:unknown host www.apple.com The speed of this response made me think that the request never even went out from the PB. So, in conclusion, it seems that: - the router is working - I can connect two computers succesfully through the router, and I can get out to the 'net through it (but only from the eMac); - the Ethernet port on the iBook is OK as I was able to connect it to the PB succesfully; - Airport on the PB is OK for the same reason that the iBooks Ethernet port was OK. So, given all the above, does anyone have any idea why I can't access the 'net from either the iBook or PB, even when they are connected to the router by the exact same cable as I succesfully use with the eMac?