[CentOS] Replacing gateway, is it bad idea?

Wed Nov 30 08:59:58 UTC 2011
Fajar Priyanto <fajarpri at arinet.org>

Hi all,
I have plan to replace my Centos5.7 VM with newer version.
The VM works as our network gateway.

I want to ask from your experience, will it be a bad decision? My
concern is that since the Mac Address of the gateway will change, will
it disrupt the network?
How fast the Switches can recognize the new mac? Any other pitfall?