diff -up dhcp-4.1.0/common/discover.c.noipv6 dhcp-4.1.0/common/discover.c
--- dhcp-4.1.0/common/discover.c.noipv6	2009-02-18 09:40:45.000000000 -1000
+++ dhcp-4.1.0/common/discover.c	2009-02-18 09:43:53.000000000 -1000
@@ -447,9 +447,11 @@ begin_iface_scan(struct iface_conf_list 
 	if (ifaces->fp6 == NULL) {
 		log_error("Error opening '/proc/net/if_inet6' to "
 			  "list IPv6 interfaces; %m");
-		close(ifaces->sock);
+		if (ifaces->sock)
+			close(ifaces->sock);
 		ifaces->sock = -1;
-		fclose(ifaces->fp);
+		if (ifaces->fp)
+			fclose(ifaces->fp);
 		ifaces->fp = NULL;
 		return 0;
 	}
@@ -719,7 +721,7 @@ next_iface(struct iface_info *info, int 
 		return 1;
 	}
 #ifdef DHCPv6
-	if (!(*err)) {
+	if (!(*err) && ifaces->fp6) {
 		return next_iface6(info, err, ifaces);
 	}
 #endif
@@ -736,7 +738,8 @@ end_iface_scan(struct iface_conf_list *i
 	close(ifaces->sock);
 	ifaces->sock = -1;
 #ifdef DHCPv6
-	fclose(ifaces->fp6);
+	if (ifaces->fp6)
+		fclose(ifaces->fp6);
 	ifaces->fp6 = NULL;
 #endif
 }