IPv6 support compiles on both glibc 2.0 and 2.1.

TODO

@@ -7,10 +7,6 @@ Core
 
 - krt: rescan interfaces when route addition fails?
 
-- tagging of external routes?
-
-- configure: IPv6 on glibc 2.0?
-
 - Makefile: install target?
 
 - forgetting device routes???

sysdep/linux/sysio.h

@@ -8,8 +8,10 @@
 
 #ifdef IPV6
 
-#ifdef CONFIG_IPV6_GLIBC_20
+#ifndef IPV6_UNICAST_HOPS
+/* Needed on glibc 2.0 systems */
 #include <linux/in6.h>
+#define CONFIG_IPV6_GLIBC_20
 #endif
 
 static inline void