Limitations of PTP
  
  
    The following are the limitations of the current implementation
of PTP:
                - Layer 2 transport is not supported.
 
                - IPv6-UDP transport is not supported.
 
                - Multicast event messages are not supported.
 
                - One-step timestamp functionality is not supported on 1G
                Fiber ports, 10G ports on CSR switches, and stacking ports.
 
                - Peer-to-peer delay mechanism is not supported.
 
                - PTP datasets are not maintained for end-to-end transparent
                clocks.
 
                - Domain number cannot be assigned to end-to-end transparent
                clocks.
 
                - Boundary clock does not support synchronizing clocks across
                multiple domains.
 
                - Distributing clock frequency recovered from SyncE or from
                BITS or from a TDM port over PTP is not supported.
 
                - Ordinary clock master (Grandmaster) mode is not
                supported.
 
                - Synchronizing system time with the time recovered from PTP
                event messages is not supported.
 
                - Time of Day (ToD) output and inputs are not supported.
 
                - Unicast message negotiation on clock ports is not
                supported.
 
                - PTP cannot be used if network clock source is configured as
                BITS.