Comment 9 for bug 58927

It is definitely a router dependent problem which happens when DHCP asks for interface-mtu and the router reports some too low value (which is 64 in all ifconfig outputs attached to this report). A simple way to check if this is the problem, and not something else, is to check what "ifconfig" says for the MTU value after DHCP has asked the address. MTU is 1500 by default, but anything over 576 is ok, lower than that can cause problems.

Moky, if one computer with edgy works ok with that router and another not, maybe you have set up the network with static IP in the computer which works? In that case DHCP would have no chance to set the MTU to wrong value. Network card or driver should have no effect to this...

Anyway, the best way to fix this is to remove "interface-mtu" from /etc/dhcp3/dhclient.conf request-line and reboot the computer (so that MTU is reset to default value). And some ubuntu dev should do that for the dhcp3-client package so that we won't have to take a count how many ~broken routers there are in the world ;)