Index: sys/netinet/in_pcb.c
===================================================================
--- sys/netinet/in_pcb.c	(revision 225885)
+++ sys/netinet/in_pcb.c	(working copy)
@@ -575,8 +575,7 @@ in_pcbbind_setup(struct inpcb *inp, struct sockadd
 				     ntohl(t->inp_faddr.s_addr) == INADDR_ANY) &&
 				    (ntohl(sin->sin_addr.s_addr) != INADDR_ANY ||
 				     ntohl(t->inp_laddr.s_addr) != INADDR_ANY ||
-				     (t->inp_socket->so_options &
-					 SO_REUSEPORT) == 0) &&
+				     (t->inp_flags2 & INP_REUSEPORT) == 0) &&
 				    (inp->inp_cred->cr_uid !=
 				     t->inp_cred->cr_uid))
 					return (EADDRINUSE);
@@ -595,14 +594,15 @@ in_pcbbind_setup(struct inpcb *inp, struct sockadd
 				    (reuseport & tw->tw_so_options) == 0)
 					return (EADDRINUSE);
 			} else if (t &&
-			    (reuseport & t->inp_socket->so_options) == 0) {
+			    (reuseport == 0 ||
+			    (t->inp_flags2 & INP_REUSEPORT) == 0)) {
 #ifdef INET6
 				if (ntohl(sin->sin_addr.s_addr) !=
 				    INADDR_ANY ||
 				    ntohl(t->inp_laddr.s_addr) !=
 				    INADDR_ANY ||
-				    INP_SOCKAF(so) ==
-				    INP_SOCKAF(t->inp_socket))
+				    (inp->inp_vflag & INP_IPV6PROTO) == 0 ||
+				    (t->inp_vflag & INP_IPV6PROTO) == 0)
 #endif
 				return (EADDRINUSE);
 			}
@@ -1867,6 +1867,11 @@ in_pcbinshash_internal(struct inpcb *inp, int do_p
 	KASSERT((inp->inp_flags & INP_INHASHLIST) == 0,
 	    ("in_pcbinshash: INP_INHASHLIST"));
 
+	if ((inp->inp_socket->so_options & SO_REUSEPORT) != 0 ||
+	    (IN_MULTICAST(ntohl(inp->inp_laddr.s_addr)) &&
+	    (inp->inp_socket->so_options & SO_REUSEADDR) != 0))
+		inp->inp_flags2 |= INP_REUSEPORT;
+
 #ifdef INET6
 	if (inp->inp_vflag & INP_IPV6)
 		hashkey_faddr = inp->in6p_faddr.s6_addr32[3] /* XXX */;
Index: sys/netinet/in_pcb.h
===================================================================
--- sys/netinet/in_pcb.h	(revision 225885)
+++ sys/netinet/in_pcb.h	(working copy)
@@ -540,6 +540,7 @@ void 	inp_4tuple_get(struct inpcb *inp, uint32_t *
 #define	INP_LLE_VALID		0x00000001 /* cached lle is valid */	
 #define	INP_RT_VALID		0x00000002 /* cached rtentry is valid */
 #define	INP_PCBGROUPWILD	0x00000004 /* in pcbgroup wildcard list */
+#define	INP_REUSEPORT		0x00000008 /* socket SO_REUSEPORT option is set */
 
 /*
  * Flags passed to in_pcblookup*() functions.