In a Switch Stack what is the StackSub port?

[Ashyuriel]

Hi All,

First time poster, but long time reader. 

Had a question that google searches don't seem to help provide answers for please. In a switch stack, when polling stackport data via SNMP, I'm getting data as per the below (3750E switch):

StackPort - 3

StackSub - 6

What is the StackSub port in reference to? Am assuming that the StackPort 3 are the 3 specific cards and the StackSub references the 2 Stack ports per card? Is this correct? 

Many thanks in advance.

[andresfr · Accepted solution]

Hello Ashyuriel,

Yes, normally the StackSub will make reference to a stack port on the switch. For instance,

If you see the following message:

StackSub-St2-1 Down

It would mean that stack port 1 on switch 2 in the stack is down and that there might be a layer 1 issue (data stack cable is not connected properly or is damaged, or the stack port itself is failing)

So, in your example, if you're having a stack of 3 switches, your assumption would be correct.

You can also check what is the corresponding OID and then see if you can find more details by using the Cisco SNMP Object Navigator:

http://snmp.cloudapps.cisco.com/Support/SNMP/do/BrowseOID.do?local=en

Regards,

[Ashyuriel]

Hi andresfr,

Many thanks for your aid.