1 files changed, 6 insertions, 0 deletions
diff --git a/lib/ip.h b/lib/ip.h
index c3683992..87cd3aa9 100644
--- a/lib/ip.h
+++ b/lib/ip.h
@@ -35,4 +35,10 @@
 #define SCOPE_SITE 2
 #define SCOPE_UNIVERSE 3
 
+/*
+ *	Is it a valid network prefix?
+ */
+
+#define ip_is_prefix(a,l) (!ipa_nonzero(ipa_and(a, ipa_not(ipa_mkmask(l)))))
+
 #endif