diff -u traceroute.orig/Makefile traceroute/Makefile
--- traceroute.orig/Makefile	Fri Aug 28 01:40:36 1998
+++ traceroute/Makefile	Wed May 17 21:58:24 2000
@@ -42,7 +42,7 @@
 SYSDEFS = -D_BSD_SOURCE
 #endif
 
-SYSDEFS =
+SYSDEFS = -DLINUX_IPSUM 
 
 # ----------------------------------------------------------------------
 # Configuration definitions.
@@ -77,7 +77,7 @@
 DEFS = $(CONFIGDEFS) $(SYSDEFS) $(INCLUDES)
 
 COPTS =
-COPTS = -O
+COPTS = -O3
 
 CFLAGS = $(COPTS) $(DEFS)
 
@@ -85,7 +85,7 @@
 CC = /usr/ucb/cc			#if defined(solaris) && BSD
 CC = /bin/cc -arch m68k -arch i386	#if defined(next)
 CC = /bin/cc
-CC = cc
+CC = gcc
 
 # ----------------------------------------------------------------------
 # Linking definitions.
diff -u traceroute.orig/conf.h traceroute/conf.h
--- traceroute.orig/conf.h	Sun Dec 29 17:50:49 1996
+++ traceroute/conf.h	Thu May 18 23:17:59 2000
@@ -14,6 +14,7 @@
 #define	NEW_PROTEON_TTL	59	/* Proteon 8.2 and higher */
 #define	OLD_BSD_TCP	30
 #define	NEW_BSD_TCP	60
+#define	CISCO_AND_OTHER	64
 
 /*
  * Table of MTU sizes in decreasing order. See RFC 1191 for details.
diff -u traceroute.orig/linux.h traceroute/linux.h
--- traceroute.orig/linux.h	Wed Aug 26 03:18:45 1998
+++ traceroute/linux.h	Wed May 17 21:59:23 2000
@@ -86,13 +86,13 @@
 #define n_long  u_int			/* redefine for 64-bit machines */
 #define n_time  u_int			/* redefine for 64-bit machines */
 
-struct icmp {
-	u_char	icmp_type;		/* type of message, see below */
-	u_char	icmp_code;		/* type sub code */
-	u_short	icmp_cksum;		/* ones complement cksum of struct */
+/* struct icmp {
+	u_char	icmp_type;	
+	u_char	icmp_code;
+	u_short	icmp_cksum;	
 	union {
-		u_char ih_pptr;			/* ICMP_PARAMPROB */
-		struct in_addr ih_gwaddr;	/* ICMP_REDIRECT */
+		u_char ih_pptr;	
+		struct in_addr ih_gwaddr;	
 		struct ih_idseq {
 			n_short	icd_id;
 			n_short	icd_seq;
@@ -112,7 +112,6 @@
 		} id_ts;
 		struct id_ip  {
 			struct ip idi_ip;
-			/* options and then 64 bits of data */
 		} id_ip;
 		n_long	id_mask;
 		char	id_data[1];
@@ -123,7 +122,7 @@
 #define	icmp_ip		icmp_dun.id_ip.idi_ip
 #define	icmp_mask	icmp_dun.id_mask
 #define	icmp_data	icmp_dun.id_data
-};
+}; */
 
 #define	ICMP_MINLEN	8		/* abs minimum */
 
@@ -170,10 +169,8 @@
  * Definitions needed for the tcp header structure.
  */
 
-#if 0
 #define th_sport	source
 #define th_dport	dest
-#endif
 
 /*
  * Some IP options have different names as well.
diff -u traceroute.orig/traceroute.c traceroute/traceroute.c
--- traceroute.orig/traceroute.c	Mon Apr  3 07:06:53 2000
+++ traceroute/traceroute.c	Thu May 18 23:18:11 2000
@@ -3083,6 +3083,7 @@
 	    case NEW_PROTEON_TTL:
 	    case OLD_BSD_TCP:
 	    case NEW_BSD_TCP:
+	    case CISCO_AND_OTHER:
 		return(TRUE);
 	}