Jan Echternach's string_to_number bignum fixes.
diff --git a/iptables.c b/iptables.c
index 92f0175..2f18826 100644
--- a/iptables.c
+++ b/iptables.c
@@ -200,6 +200,8 @@
 	{ "tcp", IPPROTO_TCP },
 	{ "udp", IPPROTO_UDP },
 	{ "icmp", IPPROTO_ICMP },
+	{ "esp", IPPROTO_ESP },
+	{ "ah", IPPROTO_AH },
 	{ "all", 0 },
 };