Getting MAC address table through SNMP on Cisco switch

[ofer1]

Hi everyone,

I have a few Cisco SG220 switches which I am trying to query through SNMP.

Specifically, I am trying to get the dot1dTpFdbTable from the bridge-mib.

I know that bridge-mib uses community string indexing using the community@vlanId format to access the table separately for each vlan, but I can't get this to work.

For the community string "public", if I try to access the dot1dTpFdbTable directly, I get an empty table.

If I use the community string "public@1", I do not get a response at all from the switch. It seems that community string indexing is just not working on this switch.

Since the only way to get the dot1dTpFdbTable is using community string indexing, and the switch does not respond to those community strings, it seems there is no way to get this data over SNMP? Am I missing something here?

If I connect to the switch over SSH and use the show mac address-table command, I get the expected result.

In addition, I also have a Cisco router which does respond to getting the bridge-mib tables using community string indexing.

Thanks

[balaji.bandi]

Not much experience on these model : check below thread help you :

https://community.cisco.com/t5/switching/how-do-i-get-mac-address-table-via-snmp/td-p/2735738

[ofer1]

Thanks,

I have seen that thread, but don't see anything there that helps in this situation. I am able to get this information from a different Cisco router that I have in the environment, but for some reason the information is not available from the switches.

[balaji.bandi · Accepted solution]

Cisco SG220  - these very low end switch, so very less features available as per i know.

Only you can do offload from the device or export to any TFTP to proces MAC information as per your requirement.

[ofer1]

Ok, thanks.

I guess that it it not supported on this switch. I just couldn't find any documentation on this either...

[ofer1 · Accepted solution]

Just in case anyone has this issue, I found a solution and am updating here.

The switch does not support the dot1dTpFdbTable in Bridge-Mib, but it does support the dot1qTpFdbTable available in Q-Bridge-Mib.

This table has similar data to the dot1dTpFdbTable. It still did not have values for the addresses in the table itself, but the addresses could be extracted from the indexes of the table rows.