Using SNMP to Find a Port Number from a MAC Address on a clustered Switch

[jerkernyberg]

Hello all,

I'm trying to use SNMP to find the Port Number from a MAC address on our switches.

I follow the procedure described in this document which works fine for most of our switches:

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a00801c9199.shtml

But in some locations the switches are clustered and only the command switch has an IP address.

As far as I understand the members switches should he accessible with community name MYCOMMUNITY@es1. But this collides with the naming for VLANS which may be reached at MYCOMMUNITY@VLAN. And I need to specifiy the VLAN to get the correct Port Name, if I follow the procedure above.

Is there any way I can solve this?

One possible solution would be to give IP addresses to the member switches too. I have not tried it yet. One of the reasons to cluster the switches was to save real IP-addresses and not have to give them private addresses.

[jerkernyberg]

Here is an example of how it looks like, slightly anonymized. It seems like it is possible to talk SNMP to the cluster command switch but the requests to the others are not proxied corrrectly, at least not with this syntax.

$ snmpbulkwalk -r 1 -t 1 -c COMMUNITY@es0@1 10.0.0.1 .1.3.6.1.2.1.17.4.3.1.2.A.B.C.X.Y.Z

SNMPv2-SMI::mib-2.17.4.3.1.2.A.B.C.X.Y.Z = INTEGER: 50

$ snmpbulkwalk -r 1 -t 1 -c COMMUNITY@es1@1 10.0.0.1 .1.3.6.1.2.1.17.4.3.1.2.A.B.C.X.Y.Z

Timeout: No Response from 10.0.0.1