Index: contrib/traceroute/as.c
===================================================================
--- contrib/traceroute/as.c	(revision 366529)
+++ contrib/traceroute/as.c	(working copy)
@@ -119,7 +119,7 @@
 }
 
 unsigned int
-as_lookup(void *_asn, char *addr, sa_family_t family)
+as_lookup(void *_asn, char *addr, sa_family_t family, int *status)
 {
 	struct aslookup *asn = _asn;
 	char buf[1024];
@@ -129,8 +129,16 @@
 	as = 0;
 	rc = dlen = 0;
 	plen = (family == AF_INET6) ? 128 : 32;
-	(void)fprintf(asn->as_f, "!r%s/%d,l\n", addr, plen);
-	(void)fflush(asn->as_f);
+	*status = fprintf(asn->as_f, "!r%s/%d,l\n", addr, plen);
+	if (*status < 0) {
+		*status = errno;
+		return 0;
+	}
+	*status = fflush(asn->as_f);
+	if (*status == EOF) {
+		*status = errno;
+		return 0;
+	}
 
 #ifdef AS_DEBUG_FILE
 	if (asn->as_debug) {
@@ -139,7 +147,14 @@
 	}
 #endif /* AS_DEBUG_FILE */
 
-	while (fgets(buf, sizeof(buf), asn->as_f) != NULL) {
+	while (1) {
+		if (fgets(buf, sizeof(buf), asn->as_f) == NULL) {
+			if(feof(asn->as_f) || ferror(asn->as_f)) {
+				*status = EIO;
+				return 0;
+			}
+			break;
+		}
 		buf[sizeof(buf) - 1] = '\0';
 
 #ifdef AS_DEBUG_FILE
Index: contrib/traceroute/traceroute.c
===================================================================
--- contrib/traceroute/traceroute.c	(revision 366529)
+++ contrib/traceroute/traceroute.c	(working copy)
@@ -356,7 +356,7 @@
 int nflag;			/* print addresses numerically */
 int as_path;			/* print as numbers for each hop */
 char *as_server = NULL;
-void *asn;
+void *as_lookup_conn = NULL;
 #ifdef CANT_HACK_IPCKSUM
 int doipcksum = 0;		/* don't calculate ip checksums by default */
 #else
@@ -992,8 +992,8 @@
 	}
 
 	if (as_path) {
-		asn = as_setup(as_server);
-		if (asn == NULL) {
+		as_lookup_conn = as_setup(as_server);
+		if (as_lookup_conn == NULL) {
 			Fprintf(stderr, "%s: as_setup failed, AS# lookups"
 			    " disabled\n", prog);
 			(void)fflush(stderr);
@@ -1251,8 +1251,8 @@
 		    (unreachable > 0 && unreachable >= nprobes - 1))
 			break;
 	}
-	if (as_path)
-		as_shutdown(asn);
+	if (as_lookup_conn)
+		as_shutdown(as_lookup_conn);
 	exit(0);
 }
 
@@ -1705,6 +1705,7 @@
 {
 	register struct ip *ip;
 	register int hlen;
+	int asn, status;
 	char addr[INET_ADDRSTRLEN];
 
 	ip = (struct ip *) buf;
@@ -1713,8 +1714,25 @@
 
 	strlcpy(addr, inet_ntoa(from->sin_addr), sizeof(addr));
 
-	if (as_path)
-		Printf(" [AS%u]", as_lookup(asn, addr, AF_INET));
+	while (as_path) {
+		asn = as_lookup(as_lookup_conn, addr, AF_INET, &status);
+		if (status) {
+			as_shutdown(as_lookup_conn);
+			as_lookup_conn = as_setup(as_server);
+			if (as_lookup_conn == NULL) {
+				Fprintf(stderr, "%s: as_setup failed, AS# lookups"
+						" disabled\n", prog);
+				(void)fflush(stderr);
+				as_path = 0;
+				break;
+			}
+			else
+				continue;
+		}
+		if (asn > 0)
+			Printf(" [AS%u]", asn);
+		break;
+	}
 
 	if (nflag)
 		Printf(" %s", addr);
Index: usr.sbin/traceroute6/traceroute6.c
===================================================================
--- usr.sbin/traceroute6/traceroute6.c	(revision 366529)
+++ usr.sbin/traceroute6/traceroute6.c	(working copy)
@@ -351,7 +351,7 @@
 int lflag;			/* print both numerical address & hostname */
 int as_path;			/* print as numbers for each hop */
 char *as_server = NULL;
-void *asn;
+void *as_lookup_conn = NULL;
 
 int
 main(int argc, char *argv[])
@@ -871,8 +871,8 @@
 	}
 
 	if (as_path) {
-		asn = as_setup(as_server);
-		if (asn == NULL) {
+		as_lookup_conn = as_setup(as_server);
+		if (as_lookup_conn == NULL) {
 			fprintf(stderr,
 			    "traceroute6: as_setup failed, AS# lookups"
 			    " disabled\n");
@@ -880,6 +880,8 @@
 			as_path = 0;
 		}
 	}
+	if (as_path)
+	        signal(SIGPIPE, SIG_IGN);
 
 	/*
 	 * Message to users
@@ -977,8 +979,8 @@
 			exit(0);
 		}
 	}
-	if (as_path)
-		as_shutdown(asn);
+	if (as_lookup_conn)
+		as_shutdown(as_lookup_conn);
 
 	exit(0);
 }
@@ -1487,13 +1489,32 @@
 print(struct msghdr *mhdr, int cc)
 {
 	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
+	int asn, status;
 	char hbuf[NI_MAXHOST];
 
 	if (getnameinfo((struct sockaddr *)from, from->sin6_len,
 	    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
 		strlcpy(hbuf, "invalid", sizeof(hbuf));
-	if (as_path)
-		printf(" [AS%u]", as_lookup(asn, hbuf, AF_INET6));
+
+	while (as_path) {
+		asn = as_lookup(as_lookup_conn, hbuf, AF_INET6, &status);
+		if (status) {
+			as_shutdown(as_lookup_conn);
+			as_lookup_conn = as_setup(as_server);
+			if (as_lookup_conn == NULL) {
+				fprintf(stderr, "traceroute6: as_setup failed, AS# lookups"
+						" disabled\n");
+				(void)fflush(stderr);
+				as_path = 0;
+				break;
+			}
+			else
+				continue;
+		}
+		if (asn > 0)
+			printf(" [AS%u]", asn);
+		break;
+	}
 	if (nflag)
 		printf(" %s", hbuf);
 	else if (lflag)