cisco router 2651XM
16 port switch module NM-16ESW fitted.
I have a web/email server (server A) plugged into the switch module in my router and sometimes I need to turn this server off and turn on a duplicate/replacement server (server B) which uses the same ip addresses but is connected to a different port (still in the switch module). Naturally I don't run them both at the same time. Problem is when server B comes on none of the web or email services work. I have a hunch the router 'remembers' the port where server A is and sticks to that port. I find that rebooting the router sorts it out but maybe there's an easier solution...? I need to make the router 'forget' server A and pick up server B. Thanks for any help.
Have you tried clearing the arp table on the router and the mac-address table on the switch ? ie.
clear mac-address-table dynamic interface