This table provides network connection information to the MTA. It is a two-dimensional table providing information about each active network connection. Connection information is not provided for other servers.
Below is an example of data from applTable (mib-220.127.116.11).
assocTable: assocRemoteApplication.1.1 = 18.104.22.168 (1) assocApplicationProtocol.1.1 = applTCPProtoID.25 (2) assocApplicationType.1.1 = peerinitiator(3) (3) assocDuration.1.1 = 400 (4) ...
In the .x.y suffix (1.1), x is the application index, applIndex, and indicates which application in the applTable is being reported on. In this case, the MTA. The y serves to enumerate each of the connections for the application being reported on.
The source IP address of the remote SMTP client.
This is an OID indicating the protocol being used over the network connection. aplTCPProtoID indicates the TCP protocol. The .n suffix indicates the TCP port in use and .25 indicates SMTP which is the protocol spoken over TCP port 25.
It is not possible to know if the remote SMTP client is a user agent (UA) or another MTA. As such, the subagent always reports peer-initiator; ua-initiator is never reported.
This is an SNMP TimeInterval and has units of hundredths of seconds. In this example, the connection has been open for 4 seconds.
This table is used to diagnose active problems. For example, if you suddenly have 200,000 inbound connections, this table can let you know where they are coming from.