diff --color -ru dhcp-4.3.6.old-patch/common/lpf.c dhcp-4.3.6.patch/common/lpf.c
--- dhcp-4.3.6.old-patch/common/lpf.c	2021-07-29 19:39:46.408565392 +0200
+++ dhcp-4.3.6.patch/common/lpf.c	2021-07-29 21:49:36.240432985 +0200
@@ -118,6 +118,12 @@
 		log_fatal ("Open a socket for LPF: %m");
 	}
 
+       	/* ZOC: Set SO_PRIORITY (skb->priority in Linux kernel) to 6.
+       	    vlan code will then map this priority to 802.1p priority according
+       	    to egress configuration for the VLAN */
+       	int val = 6;
+       	setsockopt(sock, SOL_SOCKET, SO_PRIORITY, &val, sizeof (val));
+
 	memset (&ifr, 0, sizeof ifr);
 	strncpy (ifr.ifr_name, (const char *)info -> ifp, sizeof ifr.ifr_name);
 	ifr.ifr_name[IFNAMSIZ-1] = '\0';
@@ -143,7 +149,7 @@
 		log_fatal ("Bind socket to interface: %m");
 
 	}
-
+	
 	return sock;
 }
 #endif /* USE_LPF_SEND || USE_LPF_RECEIVE */