Adding a new switch to a Cisco 3750 switch stack

mitchen · ‎11-03-2008

I currently have 7 Cisco 3750 switches in a stack, connected as follows:

Switch 1 P1 to Switch 2 P2

Switch 1 P2 to Switch 7 P1

Switch 2 P1 to Switch 3 P2

Switch 2 P2 to Switch 1 P1

Switch 3 P1 to Switch 4 P2

Switch 3 P2 to Switch 2 P1

Switch 4 P1 to Switch 5 P2

Switch 4 P2 to Switch 3 P1

Switch 5 P1 to Switch 6 P2

Switch 5 P2 to Switch 4 P1

Switch 6 P1 to Switch 7 P2

Switch 6 P2 to Switch 5 P1

Switch 7 P1 to Switch 1 P2

Switch 7 P2 to Switch 7 P1

I want to add an additional Cisco 3750 switch to this stack. What's the best way of going about this, with minimum downtime?

I know I should upgrade the new switch to the same IOS level as the existing switches and give it a low priority to avoid it becoming the master switch and that I should make sure it is powered off when hooking it up to the stacking cables.

But, can anyone suggest the best way to cable it into the existing stack?

Should I just break the connection between Switch 1 and 7 and reconnect it from Switch 1 to the new Switch 8? Then add another connection from Switch 7 to Switch 8?

Is there anything else I need to do or be aware of?

Thanks.

Prashanth Krishnappa · ‎11-03-2008

There is tech tip for this

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_example09186a00807811ad.shtml#stack3

mitchen · ‎11-04-2008

Thanks. So, based on the link you have sent me, if I carry out the following steps should that do the trick for me?

1. Change Switch IOS version to same version as switches already in the stack

2. Change the switch priority of the switch to be added to "1" (to prevent it becoming a stackmaster in future)

switch 8 priority 1

3. Power off the switch that is to be added.

4. Disconnect stack cable at Switch 7 Port 1 and reconnect to port 1 on new switch. (i.e. this will now be a connection between Switch 1 and Switch 8)

5. Connect stack cable between Switch 7 Port 1 and port 2 on new switch. (i.e. this will now be a connection between Switch 7 and Switch 8)

6. Power on the newly added switch.

7. After the new switch comes up, issue the command show switch to verify stack membership.