I was running Wireshark on my Orion server with a capture filter on one Layer-2 switch. While monitoring the traffic, I noticed that there were SNMP Get and GetBulk requests from the Orion server that had the community string set to my RO value followed by an @ sign and then what looks like the VLAN number. There will be several SNMP requests, then the commuity string value will change to a value with the next VLAN number. This is a layer 2 switch that learns VLAN info via VTP.
I need to spend a llittle time studying the SNMP Get request to see what was being requested, but has anyone seen this.
What you are seeing is likely SNMP community string indexing. In cases where multiple instances of a mib are present, such as the case of the BRIDGE-MIB, where there is actually a mib table associated with each VLAN, the method used to specify which table to get is by appending "@VLAN ID" to the community string.... I think....