diff -NarU5 ipsec-tools-0.7.0-cvs070822.orig/src/racoon/isakmp.c ipsec-tools-0.7.0-cvs070822/src/racoon/isakmp.c
--- ipsec-tools-0.7.0-cvs070822.orig/src/racoon/isakmp.c	2007-07-18 08:07:51.000000000 -0400
+++ ipsec-tools-0.7.0-cvs070822/src/racoon/isakmp.c	2007-08-22 13:04:33.000000000 -0400
@@ -1722,10 +1722,24 @@
 			    strerror(errno));
 			return -1;
 		}
 #endif
 
+		if (setsockopt(p->sock, SOL_SOCKET,
+#ifdef __linux__
+					 SO_REUSEADDR,
+#else
+					 SO_REUSEPORT,
+#endif
+					 (void *)&yes, sizeof(yes)) < 0) {
+			plog(LLV_ERROR, LOCATION, NULL,
+				"failed to set REUSE flag on %s (%s).\n",
+				saddr2str(p->addr), strerror(errno));
+			close(p->sock);
+			goto err_and_next;
+		}
+
 		if (setsockopt_bypass(p->sock, p->addr->sa_family) < 0)
 			goto err_and_next;
 
 		if (bind(p->sock, p->addr, sysdep_sa_len(p->addr)) < 0) {
 			plog(LLV_ERROR, LOCATION, p->addr,