RHEL 6.3 network services

Hello everybody,

Not sure if anyone of you encounter this issue:

RHEL6.3 server is connected to a switch, when the switch are dead, RHEL6.3 server cannot ping (that's normal), but when the switch are up back and running, the RHEL6.3 network did not up instantly, I will need to do a "service network restart" in order for it ping outside.

Any idea? Please advice.

Thanks,

kahhaw