Index: if_vlan.c
===================================================================
RCS file: /cvs/src/sys/net/if_vlan.c,v
retrieving revision 1.176
diff -u -p -r1.176 if_vlan.c
--- if_vlan.c	19 Feb 2018 08:59:52 -0000	1.176
+++ if_vlan.c	25 Mar 2018 05:12:05 -0000
@@ -261,9 +261,10 @@ vlan_start(struct ifqueue *ifq)
 			bpf_mtap_ether(ifp->if_bpf, m, BPF_DIRECTION_OUT);
 #endif /* NBPFILTER > 0 */
 
+		prio = ISSET(ifp->if_flags, IFF_LINK0) ?
+		    ifp->if_llprio : m->m_pkthdr.pf.prio;
 
 		/* IEEE 802.1p has prio 0 and 1 swapped */
-		prio = m->m_pkthdr.pf.prio;
 		if (prio <= 1)
 			prio = !prio;