freebsd/usr.sbin/mrouted/RELEASE

Id: README-3.8.mrouted,v 3.8 1995/11/29 22:23:02 fenner Rel

	IP Multicast Extensions for BSD-Derived Unix Systems

	Release 3.8
	November 29, 1995

	available from parcftp.xerox.com,
	file pub/net-research/ipmulti/mrouted3.8.tar.Z
	binaries pub/net-research/ipmulti/mrouted3.8-sparc-sunos41x.tar.Z
	         pub/net-research/ipmulti/mrouted3.8-sparc-solaris2.tar.Z
	         pub/net-research/ipmulti/mrouted3.8-i386-bsd.tar.Z
	         pub/net-research/ipmulti/mrouted3.8-alpha-osf1.tar.Z
	         pub/net-research/ipmulti/mrouted3.8-sgi-irix.tar.Z
	         pub/net-research/ipmulti/mrouted3.8-hp-hpux.tar.Z

Note: The 3.8 release is mrouted-only, and will run on top of a 3.5 kernel.
It is a drop-in replacement for mrouted 3.5, 3.6 or 3.7 .

The 3.8 release fixes the following bugs:

  o mrouted would fail to forget prunes when a neighbor went away,
    thus potentially sending traffic down a tunnel after the tunnel
    endpoint has gone down.  This was due to some research code making
    it into the "emergency" 3.7 release, sigh.

  o mrouted could send prunes with negative lifetimes.  This causes
    slightly higher prune traffic but shouldn't be any major problem.

===========
Release 3.7
November 28, 1995

The 3.7 release fixes the following bugs:

  o mrouted now ignores route reports that include bogus netmasks.
    There was a bug in 3.5 that would mangle default routes into
    tens of bogus routes; this should prevent that bug from killing
    the MBONE.

    This solution can cause route flaps and black holes until the
    3.5's are gone or all of the 3.5's neighbors are 3.7 .

  o mrouted now ignores duplicate routes.  Ciscos and the above 3.5
    bug could cause two copies of the same route to appear in a single
    routing update; mrouted would insert two copies of the same route
    into its routing table and wreak all sorts of havoc.

  o mrouted now sends a group-specific query for both retransmissions
    of a g-s query; previous versions sent a general query the second
    time.

  o mrouted now loops back multicasted mtrace responses and
    group-specific membership queries

  o mrouted now performs deterministic tiebreaking between two
    neighbors on the same vif.

  o mrouted now only does duplicate suppression on traceroute requests,
    not all traceroute packets, so that a loop can be nicely detected
    via a duplicate router instead of just a timeout.

  o the buffer size that mrouted uses has been increased to allow
    more than 16 hops in mtrace messages.

  o mtrace's hop-by-hop termination is now more likely to be correct.

  o mrinfo now waits for the responses to its retransmitted queries.

The 3.7 release has the following new features:

  o The configuration file can accept a hostname as the other end
    of a tunnel.  There must be a single name->ip mapping for the
    given name, however, or mrouted will fail to start up.

  o mrinfo now sends requests to all interfaces of a multihomed host.

  o mtrace's passive mode has been implemented.

  o The first screen of mtrace statistics is shorter and more likely
    to fit on one screen.

===========
Release 3.6
June 26, 1995

The 3.6 release fixes the following bugs:

  o mrouted would dump core when attempting to report no routes (i.e. upon
    startup, if you have no enabled phyint's)

  o mrouted would dump core if requested to traceroute a source for which it
    had no route

  o neighbor flags were not always properly updated on probe or report

  o mrouted would sometimes reply to a multicast traceroute on a disabled
    phyint; now it uses the first configured phyint to reply to traceroutes.

  o host routes (i.e. netmask 0xffffffff) works now; it was discarding
    IGMP from the host because it was coming from the "broadcast address"
    of the subnet.

  o send_igmp() now treats the failure to send an mtrace or a neighbor
    reply as informational, as opposed to warning.

  o mrouted would go into an infinite loop trying to respond to a traceroute
    for a source with a netmask of 0xffffffff.

  o vifs_with_neighbors was not being reset if the mrouted was restarted
    with SIGHUP

  o the default route was not being properly advertised to neighbors (although
    it was accepted if it was advertised to it)

  o ANSI-fication for those who it helps, still-K&R-ish for those it doesn't.

  o mtrace now attempts to trace three hops past a non-responding router,
    in the hopes that it does support traceroute but just couldn't respond
    (i.e. unicast didn't work and it can't source multicast because all its
    phyints are disabled).

  o mrinfo now times out even on a multicast router.


===========
Release 3.5
May 8, 1995

The 3.5 release has the following new features:

  o The kernel and mrouted make sure that each is the correct version, to
    prevent problems with mismatched kernel/mrouted versions.  A too-old
    mrouted will die with the error:

    can't enable DVMRP routing in kernel: Option not supported by protocol

  o mrouted can accept and propogate a default route (essential for
    heirarchical multicast routing)

  o Kernel route cache keeps source-specific routes instead of subnet routes,
    eliminating hashing and longest-match problems.
    (allows classless routing, longest-match and default routing)

  o Cached kernel routes only get deleted if no traffic is flowing, to
    facilitate multicast traceroute

  o mrouted has a new configuration file parser, which provides better error
    messages than before, and allows named boundaries (see man page)

  o added "netmask" to phyint configuration, at the suggestion of
    Anders Klemets

  o System V and FreeBSD compatibility from John Brezak <brezak@ch.hp.com>

  o phyint's can have additional subnets configured, for people with
    multiple subnets on one physical network.  mrouted.conf syntax is
    altnet 1.2.3.0, or altnet 1.2.3.0/24 if you need to specify
    a different netmask.  There can be as many altnet statements
    as you need.

  o both mrouted and the kernel now support classless addresses.

  o the kernel supports PIM assert processing by notifying the router
    when a packet arrives on the wrong interface

  o the kernel keeps additional counters, and mrouted can be compiled to
    support SNMP and the Multicast MIB

  o the packet classifier in the kernel now uses the following udp port
    ranges:
      [0, 16384) - lowest priority, unclassified
      [16384, 32768) - highest priority, i.e. audio
      [32768, 49152) - medium priority, i.e. whiteboard
      [49152, 65536) - low priority, i.e. video
    A future release of a session directory will allocate ports in these
    ranges.

  o the configuration code has been modified to default tunnels' rate_limit
    parameters to 500kbps.  This is easily modified with a rate_limit keyword
    in mrouted.conf, but should be a good default for the MBONE in general.

  o The tunnel sending code now caches a route for ip_output(), this should
    help performance on machines with lots of tunnels.

  o Dispatching for de-capsulating packets is now via protosw[], making
    reception of other raw protocols more efficient

  o Neighbor capabilities are discovered via a bitmask as opposed to
    version number.

  o Multicast traceroute code improved

  o mrouted can be compiled with Routing Support for Resource Reservation
    (RSRR), required for RSVP.


The 3.5 release fixes the following bugs:

  o The IGMPv2 query timeout field was interpreted as being in units of
    200ms as opposed to 100ms, thus the maximum timeout was set to twice
    the expected value.  This is not fatal, as mrouted always queries
    twice in the expectation that a packet could get loss, but it does
    make it less robust in the face of packet loss.

  o IGMP could report membership in local-only groups (i.e. 224.0.0.X)

  o IGMP could get confused by hearing its own new membership reports, thus
    a router would never perform fast leave.

  o IGMP could reset timers for the wrong interface.

  o mrouted put a bogus value in the maximum timeout field of IGMPv2 query
    packets.

  o Non-querier mrouters would respond to IGMP leave messages

  o mrouted was not performing fast leave properly

  o If the last member goes away on a transit network, the upstream router
    would stop forwarding even if there are downstream members.

  o Kernel hash function improved

  o Eliminated possibility of panic(): timeout in cache maintenance

  o Reordered resource allocation when sending upcall to handle failure properly

  o some endian-ness bugs squashed in mrouted, probably more to go.

  o Multicast traceroute could send a reply on a disabled interface.


This release consists of the following files:


	README-3.8.mrouted			- this file
	
	mrouted/*				- version 3.8 of mrouted,
						  mrinfo, map-mbone and
						  mtrace.

	ifconfig/*				- Changes to ifconfig to
						  show multicast interfaces

	netstat/*				- Diffs to netstat

	ping/*					- sources for ping
						  which support
						  multicasting

	mtest/*					- utility for testing
						  multicast group 
						  membership


MROUTED 3.8

Mrouted 3.8 has two optional features: SNMP and RSRR.  RSRR support
is required for running RSVP; the SNMP code, with the help of the
ISODE snmpd, implements both the Multicast MIB and the DVMRP MIB.

RSRR
----
Routing Support for Resource Reservations (RSRR) was contributed by
Daniel Zappala <daniel@isi.edu>.

To enable RSRR support, uncomment the three lines starting with
RSRR near the top of the Makefile and "make clean; make".  Or use
the prebuilt binary, mrouted.rsrr .

RSRR allows RSVP to query mrouted for its routing entry for a particular
source-group pair.  Using the routing entry and the IP_MULTICAST_VIF
socket call, RSVP can forward distinct control messages out each
outgoing interface.  This version of mrouted supports RSRR messages
using a Unix datagram socket.

RSRR currently includes two pairs of query-reply messages.  RSVP sends
an Initial Query when it starts.  Mrouted responds with an Initial Reply
that includes the set of vifs it is using, flagging those that are
administratively disabled.  When RSVP needs the routing entry for a
source-group pair, it sends a Route Query.  Mrouted responds with a
Route Reply that includes the incoming vif and outgoing vifs for the
source-group pair.

RSVP may request route change notification by setting the notification
bit in the Route Query.  If mrouted can provide route change
notification for the source-group pair, it sets the notification bit in
its Route Reply.  When the routing entry for the source-group pair
changes, mrouted sends an unsolicited Route Reply containing the new
routing information.  The initial release of mrouted 3.5 did not support
route change notification and always returned a Route Reply with the
notification bit cleared.  This release of mrouted provides route change
notification when possible.

SNMP
----
SNMP support was contributed by David Thaler <thalerd@eecs.umich.edu>.

To enable SNMP support, uncomment the six lines near the top of
the Makefile below the description of SNMP support, or use the
prebuilt binary, mrouted.snmp or mrouted.rsrr.snmp .

To link the SNMP-capable mrouted, you need the CMU libraries.
See http://nic.merit.edu/~mbone/ for a full mrouted-snmp distribution.

Make sure to add the "sysName", "sysContact", "sysVersion" and
"sysLocation" variables to your /etc/mrouted.conf if you want them
to provide anything other than default values.

Example:

sysName	"tibia"
sysContact "Bill Fenner <fenner@parc.xerox.com> +1 415 812-4816"
sysVersion "SunOS 4.1.3 and mrouted 3.8"
sysLocation "MAXC room, PARC building 35"

The SNMP version of mrouted has an additional command line flag:

  -P snmp_port
 
     Specifies a port for SNMP communication (default 161).  This option
     should be used when another SNMP daemon already exists.  The
     preferred alternate port in this case is port 9161.

The mstat(8) program allows querying of statistics using SNMP.