Merge from release 5.1.

1 files changed, 69 insertions, 25 deletions

diff --git a/usr.sbin/mrouted/mtrace.8 b/usr.sbin/mrouted/mtrace.8
index 11bffe1..4329ffb 100644
--- a/usr.sbin/mrouted/mtrace.8
+++ b/usr.sbin/mrouted/mtrace.8
@@ -29,7 +29,7 @@
 .\" Copyright (c) 1988 The Regents of the University of California.
 .\" All rights reserved.
 .\"
-.\"	$Id: mtrace.8,v 3.8.1.1 1996/11/10 22:24:15 fenner Exp $
+.\"	mtrace.8,v 5.1 1996/12/19 21:31:26 fenner Exp
 .\"
 .TH MTRACE 8 "May 8, 1995"
 .UC 6
@@ -38,6 +38,9 @@ mtrace \- print multicast path from a source to a receiver
 .SH SYNOPSIS
 .B mtrace
 [
+.B \-e
+.I extrahops
+] [
 .B \-g
 .I gateway
 ] [
@@ -48,15 +51,17 @@ mtrace \- print multicast path from a source to a receiver
 ] [
 .B \-M
 ] [
-.B \-T
-] [
 .B \-m
 .I max_hops
 ] [
 .B \-n
 ] [
+.B \-O
+] [
 .B \-p
 ] [
+.B \-P
+] [
 .B \-q
 .I nqueries
 ] [
@@ -71,6 +76,10 @@ mtrace \- print multicast path from a source to a receiver
 .B \-t
 .I ttl
 ] [
+.B \-T
+] [
+.B \-U
+] [
 .B \-v
 ] [
 .B \-w
@@ -86,9 +95,7 @@ mtrace \- print multicast path from a source to a receiver
 Assessing problems in the distribution of IP multicast traffic
 can be difficult.
 .B mtrace
-utilizes a tracing feature implemented in multicast routers
-.RB ( mrouted
-version 3.3 and later) that is
+utilizes a tracing feature implemented in multicast routers that is
 accessed via an extension to the IGMP protocol.  A trace query is
 passed hop-by-hop along the reverse path from the
 .I receiver
@@ -124,6 +131,11 @@ NOTE: For Solaris 2.4/2.5, if the multicast interface is not the default
 interface, the -i option must be used to set the local address.
 .SH OPTIONS
 .TP 8 8
+.BI \-e\  extrahops
+Try tracing
+.I extrahops
+hops past a non-responding router.
+.TP 8 8
 .BI \-g\  gwy
 Send the trace query via unicast directly to the multicast router
 .I gwy
@@ -164,8 +176,8 @@ multicast path every 10 seconds (see
 .IR stat_int ).
 .TP 8 8
 .B \-M
-Always send the response using multicast rather than attempting
-unicast first.
+Always request the response using multicast rather than attempting
+unicast for the last half of the tries.
 .TP 8 8
 .BI \-m\  n
 Set to
@@ -186,10 +198,22 @@ Set the maximum number of query attempts for any hop to
 .IR n .
 The default is 3.
 .TP 8 8
+.B \-O
+Do not use the Router-Alert IP option on those requests which need it.
+Some versions of Cisco's IOS cannot handle
+multicast traceroutes with IP options, so it may be necessary to use the
+-O flag if the last-hop router is a Cisco.
+.TP 8 8
 .B \-p
 Listen passively for multicast responses from traces initiated by
 others.  This works best when run on a multicast router.
 .TP 8 8
+.B \-P
+Loop indefinitely collecting the path every 10 seconds (see
+.B \-S
+.IR stat_int )
+and printing it when it changes.  Do not print any statistics.
+.TP 8 8
 .BI \-r\  host
 Send the trace response to
 .I host
@@ -218,6 +242,10 @@ routers" multicast group which use ttl 1.
 "Tunnel statistics" mode; show loss rates for overall traffic.
 These statistics can be extremely misleading.
 .TP 8 8
+.B \-U
+Always request the response using unicast rather than attempting
+multicast first.
+.TP 8 8
 .B \-v
 Verbose mode; show hop times on the initial trace and statistics display.
 Also show the route that was used to forward the initial trace.
@@ -321,28 +349,40 @@ increasing by one until the full path is traced or no response is
 received.  At each hop, multiple probes are sent (default is three,
 changed with
 .B \-q
-option).  The first half of the attempts (default is one) are made with
-the unicast address of the host running
-.B mtrace
-as the destination for the response.  Since the unicast route may be
-blocked, the remainder of attempts request that the response be
-multicast to mtrace.mcast.net (224.0.1.32) with the ttl set to 32 more
-than what's needed to pass the thresholds seen so far along the path
-to the receiver.  For the last quarter of the attempts (default is
-one), the ttl is increased by another 32 each time up to a maximum of
-192.  Alternatively, the ttl may be set explicitly with the
+option).  The first half of the attempts (default is two) are made with
+the reply address set to standard multicast address, mtrace.mcast.net
+(224.0.1.32) with the ttl set to 32 more than what's needed to pass the
+thresholds seen so far along the path to the receiver.  For each
+additional attempt, the ttl is increased by another 32 each time up to
+a maximum of 192.  Since the desired router may not be able to send a
+multicast reply, the remainder of the attempts request that the
+response be sent via unicast to the host running
+.B mtrace .
+Alternatively, the multicast ttl may be set explicitly with the
 .B \-t
-option and/or the initial unicast attempts can be forced to use
-multicast instead with the
+option, the initial multicast attempts can be forced to use unicast
+instead with the
+.B \-U
+option, the final unicast attempts can be forced to use multicast
+isntead with the
 .B \-M
-option.  For each attempt, if no response is received within the
-timeout, a "*" is printed.  After the specified number of attempts
-have failed,
+option, or if you specify
+.B \-UM
+.B mtrace
+will first attempt using unicast and then multicast.  For each attempt,
+if no response is received within the timeout, a "*" is printed.  After
+the specified number of attempts have failed,
 .B mtrace
 will try to query the next hop router with a DVMRP_ASK_NEIGHBORS2
 request (as used by the
 .B mrinfo
 program) to see what kind of router it is.
+.B mtrace
+will try to query three (changed with the
+.B \-e
+option) hops past a non-responding router, in the hopes that even
+though it isn't capable of sending a response, it might be capable of
+forwarding the request on.
 .SH EXAMPLES
 The output of
 .B mtrace
@@ -511,7 +551,7 @@ in no response because there was a node running an old version of
 .B mrouted
 that did not implement the multicast traceroute function, so
 .B mtrace
-switched to hop-by-hop mode.  The \*(lqRoute pruned\*(rq error code
+switched to hop-by-hop mode.  The \*(lqOutput pruned\*(rq error code
 indicates that traffic for group 224.2.143.24 would not be forwarded.
 .PP
 .nf
@@ -521,7 +561,7 @@ oak.isi.edu 108# mtrace -g 140.173.48.2 204.62.246.73 \\
 Mtrace from 204.62.246.73 to 18.26.0.151 via group 224.2.143.24
 Querying full reverse path... * switching to hop-by-hop:
   0  butter.lcs.mit.edu (18.26.0.151)
- -1  jam.lcs.mit.edu (18.26.0.144)  DVMRP  thresh^ 1  33 ms  Route pruned
+ -1  jam.lcs.mit.edu (18.26.0.144)  DVMRP  thresh^ 1  33 ms  Output pruned
  -2  bbn.dart.net (140.173.48.1)  DVMRP  thresh^ 1  36 ms  
  -3  dc.dart.net (140.173.32.2)  DVMRP  thresh^ 1  44 ms  
  -4  darpa.dart.net (140.173.240.2)  DVMRP  thresh^ 16  47 ms
@@ -545,3 +585,7 @@ program written by Van Jacobson.
 .BR mrinfo (8) ,
 .BR map-mbone (8) ,
 .BR traceroute (8)
+.SH BUGS
+.PP
+Statistics collection in passive mode doesn't always produce the same output
+as when actively collecting data.