The LAN monitoring feature has been introduced with the feature Separated Duplex. The separated LAN infrastructure of BPA and BPB increases the probability that the BP might still be able to establish LAN connections to the APs, even if there is a LAN problem at the active BP.

With the IPDA LAN L1 link monitoring feature a switch is only triggered by the LAN monitoring function if the L1 link monitoring does not work, i.e. the L1 links from the active BP and the BP are still active although all APs have failed.