Add some more details about what traceroute6 does.

Submitted by:	Orla McGann <orly@redbrick.dcu.ie>
Obtained from:	KAME
MFC after:	2 weeks

1 files changed, 40 insertions, 3 deletions

diff --git a/usr.sbin/traceroute6/traceroute6.8 b/usr.sbin/traceroute6/traceroute6.8
index 7a13f3a..99d8448 100644
--- a/usr.sbin/traceroute6/traceroute6.8
+++ b/usr.sbin/traceroute6/traceroute6.8
@@ -1,4 +1,4 @@
-.\"	$KAME: traceroute6.8,v 1.9 2002/08/30 03:56:20 onoe Exp $
+.\"	$KAME: traceroute6.8,v 1.10 2004/06/06 12:35:15 suz Exp $
 .\"
 .\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 .\" All rights reserved.
@@ -35,7 +35,7 @@
 .\"
 .Sh NAME
 .Nm traceroute6
-.Nd "print the route IPv6 packets will take to the destination"
+.Nd "print the route IPv6 packets will take to a network node"
 .\"
 .Sh SYNOPSIS
 .Nm
@@ -69,6 +69,19 @@
 .Ek
 .\"
 .Sh DESCRIPTION
+.Nm
+uses the IPv6 protocol hop limit field to elicit an ICMPv6 TIME_EXCEEDED
+response from each gateway along the path to some host.
+.Pp
+The only mandatory parameter is the destination host name or IPv6 address.
+The default probe datagram carries 12 bytes of payload,
+in addition to the IPv6 header.
+The size of the payload can be specified by giving a length 
+.Po in bytes
+.Pc 
+after the destination host name. 
+.Pp
+Other options are:
 .Bl -tag -width Ds
 .It Fl d
 Debug mode.
@@ -86,7 +99,8 @@ Normally
 .Nm
 prints only hostnames if
 .It Fl m Ar hoplimit
-Specify maximum hoplimit.
+Specify maximum hoplimit, up to 255.
+The default is 30 hops.
 .Fl n
 is not specified, and only numeric addresses if
 .Fl n
@@ -108,6 +122,29 @@ Be verbose.
 .It Fl w Ar waittime
 Specify the delay time between probes.
 .El
+.Pp
+This program prints the route to the given destination and the round-trip 
+time to each gateway, in the same manner as traceroute.
+.Pp
+Here is a list of possible annotations after the round-trip time for each gateway:
+.Pp
+.Bl -hang -offset indent
+.It  !N  
+Destination Unreachable - No Route to Host.
+.It  !P 
+Destination Unreachable - Administratively Prohibited.
+.It  !S 
+Destination Unreachable - Not a Neighbour.
+.It  !A 
+Destination Unreachable - Address Unreachable.
+.It  !
+This is printed if the hop limit is <= 1 on a port unreachable message.
+This means that the packet got to the destination,
+but that the reply had a hop limit that was just large enough to
+allow it to get back to the source of the traceroute6.
+This was more interesting in the IPv4 case,
+where some IP stack bugs could be identified by this behaviour.
+.El
 .\"
 .Sh RETURN VALUES
 The