RTMGRP_NOTIFY     538 samples/bpf/xdp_router_ipv4_user.c 	lr.nl_groups = RTMGRP_IPV6_ROUTE | RTMGRP_IPV4_ROUTE | RTMGRP_NOTIFY;
RTMGRP_NOTIFY     556 samples/bpf/xdp_router_ipv4_user.c 	la.nl_groups = RTMGRP_NEIGH | RTMGRP_NOTIFY;