Tuesday, June 12, 2007

Changing IP on Cisco/ProCurve Switch

Let's say we have the IP address assigned to vlan 1 and want to change it to On a Cisco switch, you can telnet in and send these commands to the switch:

conf t
interface vlan 1
ip address

The Cisco switch will update the IP address and disconnect your session. On a ProCurve switch, if you issue the same commands it will spit out an error saying:

"The IP address (or subnet) already exists."

If you were going through the console port, you can set the new IP using the following commands:

conf t
vlan 1
no ip address
ip address

However, you can't do that if you connect to the switch remotely. As soon as the "no ip address" command is received and processed by the switch, your session will be disconnected and you won't be able to get to the switch.

The trick to get around this issue is to make this IP address change through the switch's built-in menu system instead of using the plain old CLI.

1. Type "menu", hit Enter
2. Select "Switch Configuration"
3. Select "IP Configuration"
4. Navigate to Edit, hit Enter
5. Change the IP and then Save

You will be disconnected once you save it but you will be able to reconnect using the new IP.


Anonymous said...

Thanks for the great tip!

Anonymous said...

excellent tip