migrating to new ip addresses

[d.merry]

I need to convert the IPs for the largest part of our network from 172.30.0.0 255.255.0.0 to 172.20.6.0 255.255.252.0. I'd like to migrate it in 'sections' at a time instead of all at once.

I have a spare Cisco 2621 w/ 2 ethernet interfaces. Could I configure it with an IP from 172.30.0.0 on interface 0 and an IP from 172.20.0.0 on interface 1 and use that to route between the 2 subnets? Using this senerio both interfaces from the 2621 would connect to the same switch... ie both subnets would be on the same 'network'. Will this work? Any other ideas? Thanks, Duane.

[Amit Singh]

Duane,

I think that should work without any problems. A more practical and generally used approach is using " secondry ip addresses " under the interface.

My suggestion for you would be to define " 172.20.6.0 255.255.252.0 " secondry ip address range under the interface of the router which is currently acting as the gateway to your Lan. Onec that is done then try migrating your users to the new segment IP and once your users are on the new ip address range, you can take out the older ip address under the router interface.

HTH,Please rate if it does.

-amit singh