I had an interview the other day before a panel of very knowledgeable people and the following question was put to me: Two PCs participating in the same VLAN can communicate within their VLAN and ipconfig /all returns a valid IP address, default gateway and DNS server for both. However one PC can connect to the Internet and the other cannot. There are no ACLs to prevent Interent access so the question is why can't the one PC access the Internet? I've been thinking about this and so far I have not come up with an answer, though I will probably say "d'oh" when presented with an answer or two. Any thoughts?