Newbie Question Re: changing IP address etc

[jatkinson]

Hi

We changed upgraded our domain a while back to Windows 2000 and changed the IP infrastructure to a 172.17.0.0/16 range. Since getting interested in using CMS again I realised that my switches are on the old IP range so therefore I can't access them via the browser. I can hyperterminal in via the console port so I want to change the IP addresses for the switches/cluster so I can access them via CMS again. Can I change the IP addresses and DNS settings of the switches while they're in use by the LAN or do I need to make changes when no-one is on the network? Can someone give me a few pointers into how to change the addresses, what to look out for etc?

I have 4 switches, 3 3550XL and 1 2950, the 3 3550s were installed originally and I believe these are clustered together. I say this because I have found that the 2950 switch which was added later has DNS entries for my DNS W2K server on the 172.17.0.0/16 range and therefore has an IP address assigned that I can access the switch on via CMS but I can only see this switch in CMS and not the 3 other original switches.

Does this make sense? Shouldn't they all be clustered together so that I can use CMS to access them all via 1 IP address?

Also, and thanks for sticking with me here, what about the IOS running on them, Should they all be the same version?, the newer switch (2950) has a later IOS, how would I go about updating the IOS and to what current level.

I know I'm asking a lot of basic question for most folk so if the answers are long maybe someone could provide a few helpful links to get me going in the right direction.

Many thanks.

 

[krr]

Changing the IP address is simple. Just connect to the serial console port and press Enter. If you get "Password:" enter the access password. Anyway, you get a prompt>

> en
Password: <enter enable password>
# conf t
(config)# int vlan1
(config-if)# ip address 172.17.x.y 255.255.0.0
(config-if)# <CRTL_Z>
# wr mem
#

This will not interrupt network traffic flowing through the switch, so you can do it any time.

As for the clustering: You have to define one of the switches as "cluster command switch" and add the others as cluster members. This is best done through the web interface. The firmware versions do not have to match exactly, but shouldn't be too different. Remember that you need a special Java plugin for CMS with the latest 2950 firmware. But it will tell you, and there is a download link provided.

Firmware updates are also best done throuh the web interface. Although you can download the latest firmware from Cisco, strictly speaking, you are not allowed to install it unless you have a Cisco SmartNet contract for the switch.

Cheers *Rob

 

[jatkinson]

Cheers Rob

Thanks for the info. Is there a way to determin the cluster command switch from the command line? Is that the only switch that needs to have an IP address assigned?

Thanks again

 

[krr]

Yes, the cluster command switch is the only one that needs an IP address. Cluster members are identified by their MAC addresses.

You can configure a cluster from the command line, but I don't know the commands off the top of my head. I'd go this way:

Assign an IP address to the switch that is to become the cluster command switch, connect to it via web browser and use the web interface to configure it as cluster command switch. After that you can add the other switches to the cluster - again via web interface.

Cheers *Rob

 

[jatkinson]

Thanks for the advice, much appreciated.