dlbAthPeerTxDeauthCode is a read-only object (typed Counter32 in the MIB but used here to hold a single current value) that reports the last deauthentication reason for this associated peer, i.e. the 802.11 reason code sent with the most recent deauthentication for this client, not a count of events. A sysadmin sees this update whenever dlbAthPeerTxDeauth increments, and reading the reason code (e.g. inactivity timeout vs. explicit client-initiated leave) is the quickest way to tell why a specific client was dropped from this access point.