Question : Mac OS X (10.6) will not connect to work network

I have a rather odd situation with a Macbook Pro on our office network. Up until a few hours ago, this was on the network, through an Airport Extreme we have connected to our switch. For some reason, the connection stopped working, and for the life of me I cannot get it to renew its DHCP lease, even though several other computers are able  to get fresh leases right now.

I have tried manually entering a valid IP, mask and gateway for our network. No luck. I have confirmed that the DHCP server will issue a new IP by creating an exception for another computer's current IP, and it took the next available IP with no problem.

To make things stranger, the Macbook in question will connect to other networks without any problems.

Our network is pretty straight forward, just a Netgear router with a 8-port Linksys switch and an Apple Aiport Extreme wireless router. We have a SBS 2008 server acting as the DHCP and DNS server. At the moment that this problem started, nothing had been changed on the network, so I am really at a loss.

Any tips?

Answer : Mac OS X (10.6) will not connect to work network

Well, all this commotion, and it turns out he just had an over zealous firewall program (that I wasn't initially aware he had installed) that decided the server was trying to attack his computer, and blocked all access to it. I have configured it as a trusted site now, so this problem shouldn't happen again...