3750 stacked switches & CNA

[csisadmin]

Something wierd happening . . . A few months ago, the power supply failed on two switches on two different stacks (one on each stack). I got replacement switches from TAC and installed them. Now, I'm finding that CNA cannot see those two switches. It sees each stack, but the ports on the replacement switch are missing in CNA. They are listed in the running config for the stack and PCs connect on those ports. Everything working fine, except for CNA not being able to see the new switches. Same thing on a switch mapping application we have called Switch Inspector. It maps all ports except the ones for the newer switches. No syslog messages either.

What could be wrong?  SNMP and syslog are working for other members of the stacks.

[andtoth]

Hi,

My first guess is that the new switches got different member numbers than the previous ones had and CNA does not recognize or find the new interface numbers. As you probably know, interfaces are numbered based on the switch number. You can check the member number with the 'show switch' command by looking at the first column.

Please refer to the "Creation and Management of Cisco Catalyst 3750 Stacks" section in the following documentation:

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

Best regards,

Andras

[csisadmin]

Thanks, Andras.

I tried the sho switch and in both stacks, the newly added switch is Provisioned and MAC address is all 0's.

SW-3750-4&7FL-PTR#sho switch
                                               Current
Switch#  Role      Mac Address     Priority     State
--------------------------------------------------------
1       Member    0000.0000.0000     0         Provisioned
2       Member    001a.6caf.5f00     1         Ready
3       Member    001a.6c2a.1e00     1         Ready
*4       Master    001a.6c2a.3b80     1         Ready

SW-3750-5THFL#sho switch
                                               Current
Switch#  Role      Mac Address     Priority     State
--------------------------------------------------------
*1       Master    001a.6c11.2f80     1         Ready
2       Member    0000.0000.0000     0         Provisioned
3       Member    001a.6c2a.2f80     1         Ready

The IOS version is 12.2(25)SEE4, RELEASE SOFTWARE (fc1).

Reading from the link you included, should I do the "no switch" to remove the previous switch as in this example? I assume I should then reissue the provision statement. Should I remove the current switch from the stacking cables before the "no switch" command?

3750(config)# no switch 2 provision ws-c3750-48ts
3750(config)# exit
3750# write memory

Thanks loads for your help with this!

Mary

andtoth wrote:
Hi,
My first guess is that the new switches got different member numbers than the previous ones had and CNA does not recognize or find the new interface numbers. As you probably know, interfaces are numbered based on the switch number. You can check the member number with the 'show switch' command by looking at the first column.
Please refer to the "Creation and Management of Cisco Catalyst 3750 Stacks" section in the following documentation:
http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_example09186a00807811ad.shtml 
Best regards,
Andras

[andtoth]

Hi,

Provisioned means that the stack "slot" is reserved for a switch currently not present. If you remove a member switch from a stack temporarily, its slot is retained in provisioned state so that when you connect back the member, interface numbers and configuration are preserved. You can safely remove the provisioned entries, they are not active switches, so no need to touch any stack cables. By the way, switch numbers does not represent the physical order of the switches in the stack.

What you can try is to remove the provisoned entries by using the no switch provision ... command, then renumber the members so that they have the same numbers as it was before the replacement. For example, in your first stack, assuming the master switch should be switch #1, you can do the following steps:

- remove the provisioned switch #1 with no switch 1 provision ... command

- then use the switch 4 renumber 1 command to renumber switch #4 to #1

Andras