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Diffstat (limited to 'usr.sbin/mrouted/mrouted.8')
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diff --git a/usr.sbin/mrouted/mrouted.8 b/usr.sbin/mrouted/mrouted.8 deleted file mode 100644 index 6c4c7bd98616..000000000000 --- a/usr.sbin/mrouted/mrouted.8 +++ /dev/null @@ -1,404 +0,0 @@ -'\"COPYRIGHT 1989 by The Board of Trustees of Leland Stanford Junior University. -'\"$Id: mrouted.8,v 3.8 1995/11/29 22:37:21 fenner Rel $ -.TH MROUTED 8 -.UC 5 -.SH NAME -mrouted \- IP multicast routing daemon -.SH SYNOPSIS -.B /etc/mrouted -[ -.B \-p -] [ -.B \-c -.I config_file -] [ -.B \-d -[ -.I debug_level -]] -.SH DESCRIPTION -.I Mrouted -is an implementation of the Distance-Vector Multicast Routing -Protocol (DVMRP), an earlier version of which is specified in RFC-1075. -It maintains topological knowledge via a distance-vector routing protocol -(like RIP, described in RFC-1058), upon which it implements a multicast -datagram forwarding algorithm called Reverse Path Multicasting. -.PP -.I Mrouted -forwards a multicast datagram along a shortest (reverse) path tree -rooted at the subnet on which the datagram originates. The multicast -delivery tree may be thought of as a broadcast delivery tree that has -been pruned back so that it does not extend beyond those subnetworks -that have members of the destination group. Hence, datagrams -are not forwarded along those branches which have no listeners of the -multicast group. The IP time-to-live of a multicast datagram can be -used to limit the range of multicast datagrams. -.PP -In order to support multicasting among subnets that are separated by (unicast) -routers that do not support IP multicasting, -.I mrouted -includes support for -"tunnels", which are virtual point-to-point links between pairs of -.IR mrouted s -located anywhere in an internet. IP multicast packets are encapsulated for -transmission through tunnels, so that they look like normal unicast datagrams -to intervening routers and subnets. The encapsulation -is added on entry to a tunnel, and stripped off -on exit from a tunnel. -By default, the packets are encapsulated using the IP-in-IP protocol -(IP protocol number 4). -Older versions of -.I mrouted -tunnel using IP source routing, which puts a heavy load on some -types of routers. -This version does not support IP source route tunnelling. -.PP -The tunnelling mechanism allows -.I mrouted -to establish a virtual internet, for -the purpose of multicasting only, which is independent of the physical -internet, and which may span multiple Autonomous Systems. This capability -is intended for experimental support of internet multicasting only, pending -widespread support for multicast routing by the regular (unicast) routers. -.I Mrouted -suffers from the well-known scaling problems of any distance-vector -routing protocol, and does not (yet) support hierarchical multicast routing. -.PP -.I Mrouted -handles multicast routing only; there may or may not be unicast routing -software running on the same machine as -.IR mrouted . -With the use of tunnels, it -is not necessary for -.I mrouted -to have access to more than one physical subnet -in order to perform multicast forwarding. -.br -.ne 5 -.SH INVOCATION -.PP -If no "\-d" option is given, or if the debug level is specified as 0, -.I mrouted -detaches from the invoking terminal. Otherwise, it remains attached to the -invoking terminal and responsive to signals from that terminal. If "\-d" is -given with no argument, the debug level defaults to 2. Regardless of the -debug level, -.I mrouted -always writes warning and error messages to the system -log demon. Non-zero debug levels have the following effects: -.IP "level 1" -all syslog'ed messages are also printed to stderr. -.IP "level 2" -all level 1 messages plus notifications of "significant" -events are printed to stderr. -.IP "level 3" -all level 2 messages plus notifications of all packet -arrivals and departures are printed to stderr. -.PP -Upon startup, mrouted writes its pid to the file /etc/mrouted.pid . -.SH CONFIGURATION -.PP -.I Mrouted -automatically configures itself to forward on all multicast-capable -interfaces, i.e., interfaces that have the IFF_MULTICAST flag set (excluding -the loopback "interface"), and it finds other -.IR mrouted s -directly reachable -via those interfaces. To override the default configuration, or to add -tunnel links to other -.IR mrouted s, -configuration commands may be placed in -/etc/mrouted.conf (or an alternative file, specified by the "\-c" option). -There are four types of configuration commands: -.nf - - phyint <local-addr> [disable] [metric <m>] - [threshold <t>] [rate_limit <b>] - [boundary (<boundary-name>|<scoped-addr>/<mask-len>)] - [altnet <network>/<mask-len>] - - tunnel <local-addr> <remote-addr> [metric <m>] - [threshold <t>] [rate_limit <b>] - [boundary (<boundary-name>|<scoped-addr>/<mask-len>)] - - cache_lifetime <ct> - - pruning <off/on> - - name <boundary-name> <scoped-addr>/<mask-len> - -.fi -.PP -The file format is free-form; whitespace (including newlines) is not -significant. -The -.I boundary -and -.I altnet -options may be specified as many times as necessary. -.PP -The phyint command can be used to disable multicast routing on the physical -interface identified by local IP address <local-addr>, or to associate a -non-default metric or threshold with the specified physical interface. -The local IP address <local-addr> may be replaced by the -interface name (e.g le0). -If a phyint is attached to multiple IP subnets, describe each additional subnet -with the altnet keyword. -Phyint commands must precede tunnel commands. -.PP -The tunnel command can be used to establish a tunnel link between local -IP address <local-addr> and remote IP address <remote-addr>, and to associate -a non-default metric or threshold with that tunnel. -The local IP address <local-addr> may be replaced by the -interface name (e.g. le0). The remote IP address <remote-addr> may -be replaced by a host name, if and only if the host name has a single -IP address associated with it. -The tunnel must be set -up in the mrouted.conf files of both routers before it can be used. -'\"For backwards compatibility with older -'\".IR mrouted s, -'\"the srcrt keyword specifies -'\"encapsulation using IP source routing. -.PP -The cache_lifetime is a value that determines the amount of time that a -cached multicast route stays in kernel before timing out. The value of this -entry should lie between 300 (5 min) and 86400 (1 day). It defaults to 300. -.PP -The pruning <off/on> option is provided for -.IR mrouted -to act as a non-pruning router. It is also possible to start -.IR mrouted -in a non-pruning mode using the "-p" option on the command line. It is -expected that a router would be configured in this manner for test -purposes only. The default mode is pruning enabled. -.PP -You may assign names to boundaries to make configuration easier with -the name keyword. The boundary option on phyint or tunnel commands -can accept either a name or a boundary. -.PP -The metric is the "cost" associated with sending a datagram on the given -interface or tunnel; it may be used to influence the choice of routes. -The metric defaults to 1. Metrics should be kept as small as possible, -because -.I mrouted -cannot route along paths with a sum of metrics greater -than 31. -.LP -The threshold is the minimum IP time-to-live required for a multicast datagram -to be forwarded to the given interface or tunnel. It is used to control the -scope of multicast datagrams. (The TTL of forwarded packets is only compared -to the threshold, it is not decremented by the threshold. Every multicast -router decrements the TTL by 1.) The default threshold is 1. -.LP -In general, all -.IR mrouted s -connected to a particular subnet or tunnel should -use the same metric and threshold for that subnet or tunnel. -.PP -The rate_limit option allows the network administrator to specify a -certain bandwidth in Kbits/second which would be allocated to multicast -traffic. It defaults to 500Kbps on tunnels, and 0 (unlimited) on physical -interfaces. -.PP -The boundary option allows an interface -to be configured as an administrative boundary for the specified -scoped address. Packets belonging to this address will not -be forwarded on a scoped interface. The boundary option accepts either -a name or a boundary spec. -.PP -.I Mrouted -will not initiate execution if it has fewer than two enabled vifs, -where a vif (virtual interface) is either a physical multicast-capable -interface or a tunnel. It will log a warning if all of its vifs are -tunnels; such an -.I mrouted -configuration would be better replaced by more -direct tunnels (i.e., eliminate the middle man). -.SH "EXAMPLE CONFIGURATION" -.PP -This is an example configuration for a mythical multicast router at a big -school. -.sp -.nf -# -# mrouted.conf example -# -# Name our boundaries to make it easier -name LOCAL 239.255.0.0/16 -name EE 239.254.0.0/16 -# -# le1 is our gateway to compsci, don't forward our -# local groups to them -phyint le1 boundary EE -# -# le2 is our interface on the classroom net, it has four -# different length subnets on it. -# note that you can use either an ip address or an -# interface name -phyint 172.16.12.38 boundary EE altnet 172.16.15.0/26 - altnet 172.16.15.128/26 altnet 172.16.48.0/24 -# -# atm0 is our ATM interface, which doesn't properly -# support multicasting. -phyint atm0 disable -# -# This is an internal tunnel to another EE subnet -# Remove the default tunnel rate limit, since this -# tunnel is over ethernets -tunnel 192.168.5.4 192.168.55.101 metric 1 threshold 1 - rate_limit 0 -# -# This is our tunnel to the outside world. -# Careful with those boundaries, Eugene. -tunnel 192.168.5.4 10.11.12.13 metric 1 threshold 32 - boundary LOCAL boundary EE -.fi -.SH SIGNALS -.PP -.I Mrouted -responds to the following signals: -.IP HUP -restarts -.I mrouted . -The configuration file is reread every time this signal is evoked. -.IP INT -terminates execution gracefully (i.e., by sending -good-bye messages to all neighboring routers). -.IP TERM -same as INT -.IP USR1 -dumps the internal routing tables to /usr/tmp/mrouted.dump. -.IP USR2 -dumps the internal cache tables to /usr/tmp/mrouted.cache. -.IP QUIT -dumps the internal routing tables to stderr (only if -.I mrouted -was invoked with a non-zero debug level). -.PP -For convenience in sending signals, -.I mrouted -writes its pid to /etc/mrouted.pid upon startup. -.bp -.SH EXAMPLE -.PP -The routing tables look like this: -.nf - -Virtual Interface Table - Vif Local-Address Metric Thresh Flags - 0 36.2.0.8 subnet: 36.2 1 1 querier - groups: 224.0.2.1 - 224.0.0.4 - pkts in: 3456 - pkts out: 2322323 - - 1 36.11.0.1 subnet: 36.11 1 1 querier - groups: 224.0.2.1 - 224.0.1.0 - 224.0.0.4 - pkts in: 345 - pkts out: 3456 - - 2 36.2.0.8 tunnel: 36.8.0.77 3 1 - peers: 36.8.0.77 (2.2) - boundaries: 239.0.1 - : 239.1.2 - pkts in: 34545433 - pkts out: 234342 - - 3 36.2.0.8 tunnel: 36.6.8.23 3 16 - -Multicast Routing Table (1136 entries) - Origin-Subnet From-Gateway Metric Tmr In-Vif Out-Vifs - 36.2 1 45 0 1* 2 3* - 36.8 36.8.0.77 4 15 2 0* 1* 3* - 36.11 1 20 1 0* 2 3* - . - . - . - -.fi -In this example, there are four vifs connecting to two subnets and two -tunnels. The vif 3 tunnel is not in use (no peer address). The vif 0 and -vif 1 subnets have some groups present; tunnels never have any groups. This -instance of -.I mrouted -is the one responsible for sending periodic group -membership queries on the vif 0 and vif 1 subnets, as indicated by the -"querier" flags. The list of boundaries indicate the scoped addresses on that -interface. A count of the no. of incoming and outgoing packets is also -shown at each interface. -.PP -Associated with each subnet from which a multicast datagram can originate -is the address of the previous hop router (unless the subnet is directly- -connected), the metric of the path back to the origin, the amount of time -since we last received an update for this subnet, the incoming vif for -multicasts from that origin, and a list of outgoing vifs. "*" means that -the outgoing vif is connected to a leaf of the broadcast tree rooted at the -origin, and a multicast datagram from that origin will be forwarded on that -outgoing vif only if there are members of the destination group on that leaf. -.bp -.PP -.I Mrouted -also maintains a copy of the kernel forwarding cache table. Entries -are created and deleted by -.I mrouted. -.PP -The cache tables look like this: -.nf - -Multicast Routing Cache Table (147 entries) - Origin Mcast-group CTmr Age Ptmr IVif Forwvifs - 13.2.116/22 224.2.127.255 3m 2m - 0 1 ->13.2.116.19 ->13.2.116.196 - 138.96.48/21 224.2.127.255 5m 2m - 0 1 ->138.96.48.108 - 128.9.160/20 224.2.127.255 3m 2m - 0 1 ->128.9.160.45 - 198.106.194/24 224.2.135.190 9m 28s 9m 0P ->198.106.194.22 - -.fi -Each entry is characterized by the origin subnet number and mask and the -destination multicast group. The 'CTmr' field indicates the lifetime -of the entry. The entry is deleted from the cache table -when the timer decrements to zero. The 'Age' field is the time since -this cache entry was originally created. Since cache entries get refreshed -if traffic is flowing, routing entries can grow very old. -The 'Ptmr' field is simply a dash if no prune was sent upstream, or the -amount of time until the upstream prune will time out. -The 'Ivif' field indicates the -incoming vif for multicast packets from that origin. Each router also -maintains a record of the number of prunes received from neighboring -routers for a particular source and group. If there are no members of -a multicast group on any downward link of the multicast tree for a -subnet, a prune message is sent to the upstream router. They are -indicated by a "P" after the vif number. The Forwvifs field shows the -interfaces along which datagrams belonging to the source-group are -forwarded. A "p" indicates that no datagrams are being forwarded along -that interface. An unlisted interface is a leaf subnet with are no -members of the particular group on that subnet. A "b" on an interface -indicates that it is a boundary interface, i.e. traffic will not be -forwarded on the scoped address on that interface. -An additional line with a ">" as the first character is printed for -each source on the subnet. Note that there can be many sources in -one subnet. -.SH FILES -/etc/mrouted.conf -.br -/etc/mrouted.pid -.br -/usr/tmp/mrouted.dump -.br -/usr/tmp/mrouted.cache -.SH SEE ALSO -.BR mrinfo (8) , -.BR mtrace (8) , -.BR map-mbone (8) -.sp -DVMRP is described, along with other multicast routing algorithms, in the -paper "Multicast Routing in Internetworks and Extended LANs" by S. Deering, -in the Proceedings of the ACM SIGCOMM '88 Conference. -.SH AUTHORS -Steve Deering, Ajit Thyagarajan, Bill Fenner |