diff -ru ../fping-2.4b2_to-ipv6-orig/fping.c ./fping.c
--- ../fping-2.4b2_to-ipv6-orig/fping.c	Sun Jan 20 19:06:30 2002
+++ ./fping.c	Fri Apr 13 14:36:02 2007
@@ -283,6 +283,12 @@
 u_int count = 1;
 u_int trials;
 u_int report_interval = 0;
+int src_addr_present = 0;
+#ifndef IPV6
+struct in_addr src_addr;
+#else
+struct in6_addr src_addr;
+#endif
 
 /* global stats */
 long max_reply = 0;
@@ -408,6 +414,11 @@
 	struct protoent *proto;
 	char *buf;
 	uid_t uid;
+#ifndef IPV6
+	struct sockaddr_in sa;
+#else
+	struct sockaddr_in6 sa;
+#endif
 	/* check if we are root */
 
 	if( geteuid() )
@@ -491,7 +502,7 @@
 
 	/* get command line options */
 
-	while( ( c = getopt( argc, argv, "gedhlmnqusaAvz:t:i:p:f:r:c:b:C:Q:B:" ) ) != EOF )
+	while( ( c = getopt( argc, argv, "gedhlmnqusaAvz:t:i:p:f:r:c:b:C:Q:B:S:" ) ) != EOF )
 	{
 		switch( c )
 		{
@@ -639,6 +650,16 @@
 			generate_flag = 1;
 			break;
 
+		case 'S':
+#ifndef IPV6
+			if( ! inet_pton( AF_INET, optarg, &src_addr ) )
+#else
+			if( ! inet_pton( AF_INET6, optarg, &src_addr ) )
+#endif
+				usage();
+			src_addr_present = 1;
+			break;
+
 		default:
 			usage();
 			break;
@@ -962,6 +983,22 @@
 	if( !num_hosts )
 		exit( 2 );
 
+	/* set the source address */
+
+	if( src_addr_present )
+	{
+		memset( &sa, 0, sizeof( sa ) );
+#ifndef IPV6
+		sa.sin_family = AF_INET;
+		sa.sin_addr = src_addr;
+#else
+		sa.sin6_family = AF_INET6;
+		sa.sin6_addr = src_addr;
+#endif
+		if ( bind( s, (struct sockaddr *)&sa, sizeof( sa ) ) < 0 )
+			errno_crash_and_burn( "cannot bind source address" );
+	}
+
 	/* allocate array to hold outstanding ping requests */
 
 	table = ( HOST_ENTRY** )malloc( sizeof( HOST_ENTRY* ) * num_hosts );
@@ -2732,6 +2769,7 @@
 	fprintf( stderr, "   -Q n       same as -q, but show summary every n seconds\n" );
 	fprintf( stderr, "   -r n       number of retries (default %d)\n", retry );
 	fprintf( stderr, "   -s         print final stats\n" );
+	fprintf( stderr, "   -S addr    set source address\n" );
 	fprintf( stderr, "   -t n       individual target initial timeout (in millisec) (default %d)\n", timeout / 100 );
 	fprintf( stderr, "   -u         show targets that are unreachable\n" );
 	fprintf( stderr, "   -v         show version\n" );