This 4-byte octet string captures the DXI2 header of the last SMDS PDU that triggered the 'Dxi2 Station Id Invalid' violation, meaning the station identifier field in the DXI level-2 header didn't match what the switch expects for this port. An admin decoding these 4 bytes can determine which station ID the CPE is actually presenting, useful for catching a device that was cloned or reconfigured with the wrong station identity. For example, swapping in a spare DXI adapter without updating its configured station ID would cause this violation to appear with the old station's ID visible in the captured header.