Based on patch from redhat:  http://cvs.fedoraproject.org/viewvc/devel/dhcp/dhcp-4.1.0-missing-ipv6-not-fatal.patch?revision=1.2

--- common/discover.c.orig	2008-08-29 13:48:57.000000000 -0400
+++ common/discover.c	2009-09-08 23:32:45.000000000 -0400
@@ -443,16 +443,20 @@
 	}
 
 #ifdef DHCPv6
-	ifaces->fp6 = fopen("/proc/net/if_inet6", "r");
-	if (ifaces->fp6 == NULL) {
-		log_error("Error opening '/proc/net/if_inet6' to "
-			  "list IPv6 interfaces; %m");
-		close(ifaces->sock);
-		ifaces->sock = -1;
-		fclose(ifaces->fp);
-		ifaces->fp = NULL;
-		return 0;
-	}
+ 	if (!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 "
+				  "list IPv6 interfaces; %m");
+			close(ifaces->sock);
+			ifaces->sock = -1;
+			fclose(ifaces->fp);
+			ifaces->fp = NULL;
+			return 0;
+		}
+ 	} else {
+ 		ifaces->fp6 = NULL;
+  	}
 #endif
 
 	return 1;
@@ -719,7 +723,7 @@
 		return 1;
 	}
 #ifdef DHCPv6
-	if (!(*err)) {
+	if (!(*err) && ifaces->fp6) {
 		return next_iface6(info, err, ifaces);
 	}
 #endif
@@ -736,7 +740,8 @@
 	close(ifaces->sock);
 	ifaces->sock = -1;
 #ifdef DHCPv6
-	fclose(ifaces->fp6);
+	if (ifaces->fp6)
+		fclose(ifaces->fp6);
 	ifaces->fp6 = NULL;
 #endif
 }