diff -up dhcp-4.2.0/common/discover.c.noipv6 dhcp-4.2.0/common/discover.c
--- dhcp-4.2.0/common/discover.c.noipv6	2010-07-21 14:31:13.000000000 +0200
+++ dhcp-4.2.0/common/discover.c	2010-07-21 16:04:57.000000000 +0200
@@ -443,7 +443,7 @@ begin_iface_scan(struct iface_conf_list 
 	}
 
 #ifdef DHCPv6
-	if (local_family == AF_INET6) {
+	if ((local_family == AF_INET6) && !access("/proc/net/if_inet6", R_OK)) {
 		ifaces->fp6 = fopen("/proc/net/if_inet6", "re");
 		if (ifaces->fp6 == NULL) {
 			log_error("Error opening '/proc/net/if_inet6' to "
@@ -454,6 +454,8 @@ begin_iface_scan(struct iface_conf_list 
 			ifaces->fp = NULL;
 			return 0;
 		}
+	} else {
+		ifaces->fp6 = NULL;
 	}
 #endif
 
@@ -721,7 +723,7 @@ next_iface(struct iface_info *info, int 
 		return 1;
 	}
 #ifdef DHCPv6
-	if (!(*err)) {
+	if (!(*err) && ifaces->fp6) {
 		if (local_family == AF_INET6)
 			return next_iface6(info, err, ifaces);
 	}
@@ -740,7 +742,8 @@ end_iface_scan(struct iface_conf_list *i
 	ifaces->sock = -1;
 #ifdef DHCPv6
 	if (local_family == AF_INET6) {
-		fclose(ifaces->fp6);
+		if (ifaces->fp6)
+			fclose(ifaces->fp6);
 		ifaces->fp6 = NULL;
 	}
 #endif