This read-only Unsigned32 counts, per its source description, the number of times multiple DCBX peers were detected on this port, where a duplicate peer means more than one DCBX-speaking device is seen on what should be a point-to-point link. Admins watch this counter to catch a misconfigured shared-media segment or a rogue device injecting DCBX frames on a port that's supposed to face a single switch or NIC. For example, a nonzero and climbing MultiplePeerCount on an access port would prompt a check of what's physically connected there.