We lost our internet connection in our group the other day, when our
local LAN network was still working.

When I re-power the firewall, the internet was restored to most of
the computers.

However, there are a few computers can't get back to the internet
althought these computers can still connected within our Window Domain
and work normal in our local LAN.

I try to reboot, ipconfig/renew, or change from static IP into DHCP,
still doesn' work, while other computers with similar configuation
(Gateway, DNS/WAN) work totally fine. I try other computer with the
same network cable/connector, also work fine.

Can anyone give me a hand in this problem??