[CentOS] Replacing gateway, is it bad idea?

Wed Nov 30 13:44:36 UTC 2011
Les Mikesell <lesmikesell at gmail.com>

On Wed, Nov 30, 2011 at 2:59 AM, Fajar Priyanto <fajarpri at arinet.org> wrote:
> 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?

Switches normally flood all ports until a new mac is identified so
they will work as soon as the link comes up (which may take a few
seconds for spanning tree).  However, routers to adjacent subnets may
cache their arp table for up to 20 minutes.  You might have a problem
with inbound connections if you don't clear the arp table on whatever
is connected as the next hop.

  Les Mikesell
    lesmikesell at gmail.com