diff -Naur -x '*~' -x '*.rej' -x '*.orig' dhcp-4.2.2/common/discover.c dhcp-4.2.2-missing-ipv6-not-fatal/common/discover.c
--- dhcp-4.2.2/common/discover.c	2011-07-20 00:22:48.000000000 +0200
+++ dhcp-4.2.2-missing-ipv6-not-fatal/common/discover.c	2011-09-12 13:33:04.300509236 +0200
@@ -455,7 +455,7 @@
 	}
 
 #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", "r");
 		if (ifaces->fp6 == NULL) {
 			log_error("Error opening '/proc/net/if_inet6' to "
@@ -466,6 +466,8 @@
 			ifaces->fp = NULL;
 			return 0;
 		}
+	} else {
+		ifaces->fp6 = NULL;
 	}
 #endif
 
@@ -733,7 +735,7 @@
 		return 1;
 	}
 #ifdef DHCPv6
-	if (!(*err)) {
+	if (!(*err) && ifaces->fp6) {
 		if (local_family == AF_INET6)
 			return next_iface6(info, err, ifaces);
 	}
@@ -752,7 +754,8 @@
 	ifaces->sock = -1;
 #ifdef DHCPv6
 	if (local_family == AF_INET6) {
-		fclose(ifaces->fp6);
+		if (ifaces->fp6)
+			fclose(ifaces->fp6);
 		ifaces->fp6 = NULL;
 	}
 #endif