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 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 . 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 . 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 +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.