diff -uNr net-tools-1.51-orig/lib/masq_info.c net-tools-1.51/lib/masq_info.c
--- net-tools-1.51-orig/lib/masq_info.c	Thu Mar 18 07:53:05 1999
+++ net-tools-1.51/lib/masq_info.c	Sat Jun 12 13:36:24 1999
@@ -124,6 +124,10 @@
 	    ms->proto = "udp";
 	else if (strcmp("ICMP", buf) == 0)
 	    ms->proto = "icmp";
+	else if (strcmp("GRE", buf) == 0)
+	    ms->proto = "gre";
+	else if (strcmp("ESP", buf) == 0)
+	    ms->proto = "esp";
 	else {
 	    EINTERN("masq_info.c", "ip_masquerade unknown type");
 	    return (-1);