--- traceroute.c.orig	Mon Sep  2 14:45:19 2002
+++ traceroute.c	Sun Sep  1 10:37:47 2002
@@ -319,7 +319,7 @@
 int verbose;
 int waittime = 5;		/* time to wait for response (in seconds) */
 int nflag;			/* print addresses numerically */
-
+int incport = 1;		/* increment dest port number after each hop */
 extern int optind;
 extern int opterr;
 extern char *optarg;
@@ -441,7 +441,7 @@
 		prog = argv[0];
 
 	opterr = 0;
-	while ((op = getopt(argc, argv, "Sdnrvg:M:m:P:p:q:s:t:w:")) != EOF)
+	while ((op = getopt(argc, argv, "Sdnrvg:M:m:P:p:q:s:t:w:0")) != EOF)
 		switch (op) {
 
 		case 'S':
@@ -566,6 +566,10 @@
 			}
 			break;
 
+		case '0':
+			incport = 0;
+			break;
+
 		default:
 			usage();
 		}
@@ -1064,7 +1068,10 @@
 	struct udphdr *const udp = (struct udphdr *) outprot;
 
 	udp->uh_sport = htons(ident);
+	if (incport)
 	udp->uh_dport = htons(port + outdata->seq);
+	else
+	  udp->uh_dport = htons(port);
 	udp->uh_ulen = htons((u_short)protlen);
 }
 
@@ -1073,8 +1080,12 @@
 {
 	struct udphdr *const udp = (struct udphdr *) data;
 
+	if (incport)
 	return (ntohs(udp->uh_sport) == ident
 	    && ntohs(udp->uh_dport) == port + seq);
+	else
+	  return (ntohs(udp->uh_sport) == ident
+		  && ntohs(udp->uh_dport) == port);
 }
 
 void
@@ -1083,7 +1094,10 @@
 	struct tcphdr *const tcp = (struct tcphdr *) outprot;
 
 	tcp->th_sport = htons(ident);
+	if (incport)
 	tcp->th_dport = htons(port + outdata->seq);
+	else
+	  tcp->th_dport = htons(port);
 	tcp->th_seq = (tcp->th_sport << 16) | tcp->th_dport;
 	tcp->th_ack = 0;
 	tcp->th_off = 5;
@@ -1095,8 +1109,12 @@
 {
 	struct tcphdr *const tcp = (struct tcphdr *) data;
 
+	if (incport)
 	return (ntohs(tcp->th_sport) == ident
 	    && ntohs(tcp->th_dport) == port + seq);
+	else
+	  return (ntohs(tcp->th_sport) == ident
+		  && ntohs(tcp->th_dport) == port);
 }
 
 void
@@ -1115,6 +1133,10 @@
 {
 	struct grehdr *const gre = (struct grehdr *) data;
 
+	if (incport)
+	  return(ntohs(gre->proto) == port
+		 && ntohs(gre->callId) == ident + seq);
+	else
 	return(ntohs(gre->proto) == port
 	    && ntohs(gre->callId) == ident + seq);
 }
@@ -1125,7 +1147,10 @@
 	u_int16_t *const ptr;
 
 	ptr[0] = htons(ident);
+	if (incport)
 	ptr[1] = htons(port + outdata->seq);
+	else
+	  ptr[1] = htons(port);
 }
 
 int
@@ -1133,8 +1158,12 @@
 {
 	u_int16_t *const ptr = (u_int16_t *) data;
 
+	if (incport)
 	return(ntohs(ptr[0]) == ident
 	    && ntohs(ptr[1]) == port + seq);
+	else
+	  return(ntohs(ptr[0]) == ident
+		 && ntohs(ptr[1]) == port);
 }
 
 void