Question : Problem: Macbook Pro will not connect via internet via wifi but connects to network

Macbook Pro running 10.5.4 which apparently can connect to the internal network via wifi airport etc, but cannot surf the internet.  We can ping internal ip addresses 192.168.xxx.xxx but cannot ping names nor external ip addresses which would tell us if there some problem with resolving names.  Just this notebook has the problem and it baffles me.  Any idea

Answer : Problem: Macbook Pro will not connect via internet via wifi but connects to network

Does it work from an outside location?

What type of network are you running in house? Windows 2003/2008 or Mac OSX
Is your firewall blocking it?
Did you check your DNS settings?