Hi, We configure the DP83640 in TS_APPEND mode(TS_APPEND & TS_INSERT = 1 in PTP Receive Configuration Register 3). My customer use heavy multicast for PLC communication with our PTP ethernet switch(2-step P2P Layer 2 TC mode). They reported the multicast packet loss occur. We reconfigured the DP83640 to use PTP Receive Timestamp Register(TS_APPEND & TS_INSERT = 0). The customer reported no packet loss occur. Is this is chip limitation or bug ? Is there any work around for the issue ? Thanks.