Changing an IP address in a Cisco Switch is quite simple, where as in HP Procurve Switches if you try to change an IP address for any existing vlan you get an error message The IP address (or subnet) 10.0.0.122/23 already exists..
I will demonstrate how to change an IP address for an existing VLAN. In this example we have a VLAN 100 assigned with an IP address 10.0.0.99/23 in a HP Procurve Switch.
ip address 10.0.0.97 255.255.248.0
We will try to change the IP address in a normal way as we do in a Cisco Catalyst Switch.
ICU(config)# vlan 100
ICU(vlan-100)# ip address 10.0.0.122 255.255.254.0
The IP address (or subnet) 10.0.0.122/23 already exists..
The moment you enter the IP address command you will get an error message mentioned above.
In order to change an IP address do the following things
Log in to the Switch thro a console port.
Then from the global parameters use the following commands
no ip address 10.0.0.97 255.255.248.0
ip address 10.0.0.122 255.255.248.0
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.