$NetBSD: patch-ab,v 1.2 2024/06/25 16:24:31 ryoon Exp $

--- traceroute.c.orig	2000-04-03 14:06:53.000000000 +0000
+++ traceroute.c
@@ -297,7 +297,6 @@ static char Version[] = "@(#)traceroute.
 #define EXTERN extern
 #endif
 
-EXTERN int errno;
 EXTERN res_state_t _res;	/* defined in res_init.c */
 extern char *version;		/* program version number */
 
@@ -982,16 +981,16 @@ check_proto()
 {
 	struct protoent *proto;
 
-	proto = getprotobyname("ip");
+	proto = getprotobyname("ipv4");
 	if (proto == NULL)
 	{
-		(void) fprintf(stderr, "ip: unknown protocol\n");
+		(void) fprintf(stderr, "ipv4: unknown protocol\n");
 		exit(EX_OSFILE);
 	}
-	if (proto->p_proto != IPPROTO_IP)
+	if (proto->p_proto != IPPROTO_IPV4)
 	{
 		(void) fprintf(stderr, "ip protocol %d should be %d\n",
-			proto->p_proto, IPPROTO_IP);
+			proto->p_proto, IPPROTO_IPV4);
 		exit(EX_CONFIG);
 	}