Hi Stephen,

Seems that problem is that by default ipmonitor subscribes to the all
RTNL groups except RTMGRP_TC:
    groups = ~RTMGRP_TC;

And I assume that other netlink messages can also cause such
Timestamping w/o event message ...
So I think there should be another way than ~RTMGR_TC, and this big IF
in accept_msg can be removed.

Regards,
Vadim