diff --git a/conf.c b/conf.c
index 90d3436..3f30725 100644
--- a/conf.c
+++ b/conf.c
@@ -629,10 +629,12 @@ static unsigned int conf_ip4(unsigned int ifi,
 			    if_indextoname(ifi, ifname), strerror(-rc));
 			return 0;
 		}
+
+		if (MAC_IS_ZERO(mac))
+			memcpy(mac, MAC_LAA, ETH_ALEN);
 	}
 
-	if (IN4_IS_ADDR_UNSPECIFIED(&ip4->addr) ||
-	    MAC_IS_ZERO(mac))
+	if (IN4_IS_ADDR_UNSPECIFIED(&ip4->addr))
 		return 0;
 
 	return ifi;
@@ -688,11 +690,13 @@ static unsigned int conf_ip6(unsigned int ifi,
 			    if_indextoname(ifi, ifname), strerror(-rc));
 			return 0;
 		}
+
+		if (MAC_IS_ZERO(mac))
+			memcpy(mac, MAC_LAA, ETH_ALEN);
 	}
 
 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->addr) ||
-	    IN6_IS_ADDR_UNSPECIFIED(&ip6->addr_ll) ||
-	    MAC_IS_ZERO(mac))
+	    IN6_IS_ADDR_UNSPECIFIED(&ip6->addr_ll))
 		return 0;
 
 	return ifi;
diff --git a/util.h b/util.h
index 8c37729..ef01001 100644
--- a/util.h
+++ b/util.h
@@ -91,6 +91,7 @@
 #define PORT_IS_EPHEMERAL(port) ((port) >= PORT_EPHEMERAL_MIN)
 
 #define MAC_ZERO		((uint8_t [ETH_ALEN]){ 0 })
+#define MAC_LAA			((uint8_t [ETH_ALEN]){ BIT(1), 0, 0, 0, 0, 0 })
 #define MAC_IS_ZERO(addr)	(!memcmp((addr), MAC_ZERO, ETH_ALEN))
 
 #ifndef __bswap_constant_16