Changing Subnet Mask on a bunch of switches?

[Big Tom Davis]

I have to change the subnet mask on a bunch of 26XX switches (about 300 of em). Does anyone have an easier way to do this than going to each and every switch with a console cable and changing it?

[Matt Hobbs]

I'm thinking the way to do it remotely is to upload a new config with the revised subnet mask.

[Mohieddin Kharnoub]

Hi

Say you have 172.16.0.0/16 network range, and you need to change it to 192.168.1.1/24 range.

Add another IP address to your computer, say 192.168.1.10/24, then telnet to first switch, example 172.16.0.1,

Then what you have to do is, add another secondary IP address to Vlan1 (or to the same Vlan you are in with the switch),

Switch(Config)#vlan 1 ip add 192.168.1.100/24

then remove the old IP address:
Switch(Config)#no vlan 1 ip add 172.16.0.100/16

You will disconnected in this case, then ping the other switch's IP 192.168.1.100, and telnet to it, and you can add another new IP address or change the one you've set (192.168.1.100) ....

Good Luck !!!