Retrieve snmp info for specific VS

It is possible to do this. You need to specify the virtual server name, in (escaped, so the shell doesn't eat them) quotes. You can get the full list of possible values using the following command:

 snmpwalk -v2c -c public -OE localhost ltmVirtualServStatName
F5-BIGIP-LOCAL-MIB::ltmVirtualServStatName.\"/Common/test-vs\" = STRING: /Common/test-vs
F5-BIGIP-LOCAL-MIB::ltmVirtualServStatName.\"/Common/hud-http\" = STRING: /Common/hud-http
F5-BIGIP-LOCAL-MIB::ltmVirtualServStatName.\"/Common/test_exch.app/test_exch_combined_http\" = STRING: /Common/test_exch.app/test_exch_combined_http
F5-BIGIP-LOCAL-MIB::ltmVirtualServStatName.\"/Common/test_exch.app/test_exch_combined_https\" = STRING: /Common/test_exch.app/test_exch_combined_https

This is from my lab system with four virtual servers. You can copy and paste, or you can do the same thing manually with any defined virtual server (you must use the full name of the virtual server including its path):

 snmpget -v2c -c public localhost ltmVirtualServStatClientPktsIn.\"/Common/test_exch.app/test_exch_combined_http\"
F5-BIGIP-LOCAL-MIB::ltmVirtualServStatClientPktsIn."/Common/test_exch.app/test_exch_combined_http" = Counter64: 0

The

-OE

option tells

snmpwalk

to escape the quotes around the table indices so you can copy and paste directly to the command line - if they're not escaped, the shell eats the quotes and the SNMP tools will not handle this correctly:

 snmpget -v2c -c public localhost ltmVirtualServStatClientPktsIn."/Common/test_exch.app/test_exch_combined_http"
ltmVirtualServStatClientPktsIn./Common/test_exch.app/test_exch_combined_http: Unknown Object Identifier (Index out of range: /Common/test_exch (ltmVirtualServStatName))

This is because the actual OID is a representation of the string, not the literal string, which can be shown with the

-Ob

option to snmp tools:

 snmpget -v2c -c public -Ob localhost ltmVirtualServStatName.\"/Common/test-vs\"
F5-BIGIP-LOCAL-MIB::ltmVirtualServStatName.15.47.67.111.109.109.111.110.47.116.101.115.116.45.118.115 = STRING: /Common/test-vs

For obvious reasons, I recommend sticking with the quoted string version.