Counts packets seen by the relay agent that carry IPSec headers. Because IPSec-encapsulated DHCP-looking traffic can't be properly parsed and option-82-tagged by the relay's classification logic, a nonzero and rising value here flags traffic the relay is encountering but can't fully process as expected, which is unusual for typical client-side DHCP traffic and worth investigating as a possible misconfiguration or unexpected tunnel. Seeing this counter increment on an access port that's supposed to carry only plain DHCP broadcasts would suggest an IPSec-capable device is unexpectedly sending encapsulated traffic that matches the relay's packet filter.