Distance Vector Multicast Routing Protocol (RFC1075)
Original Publication Date: 1988-Nov-01
Included in the Prior Art Database: 2019-Feb-15
Internet Society Requests For Comment (RFCs)
D. Waitzman: AUTHOR [+2]
This RFC describes a distance-vector-style routing protocol for routing multicast datagrams through an internet. It is derived from the Routing Information Protocol (RIP), and implements multicasting as described in RFC-1054. This is an experimental protocol, and its implementation is not recommended at this time.
Network Working Group D. Waitzman Request For Comments: 1075 C. Partridge BBN STC S. Deering Stanford University November 1988
Distance Vector Multicast Routing Protocol
1. Status of this Memo
This RFC describes a distance-vector-style routing protocol for routing multicast datagrams through an internet. It is derived from the Routing Information Protocol (RIP) , and implements multicasting as described in RFC-1054. This is an experimental protocol, and its implementation is not recommended at this time. Distribution of this memo is unlimited.
A draft standard for multicasting over IP networks now exists , but no routing protocols to support internetwork multicasting are available. This memo describes an experimental routing protocol, named DVMRP, that implements internetwork multicasting. DVMRP combines many of the features of RIP  with the Truncated Reverse Path Broadcasting (TRPB) algorithm described by Deering .
DVMRP is an "interior gateway protocol"; suitable for use within an autonomous system, but not between different autonomous systems. DVMRP is not currently developed for use in routing non-multicast datagrams, so a router that routes both multicast and unicast datagrams must run two separate routing processes. DVMRP is designed to be easily extensible and could be extended to route unicast datagrams.
DVMRP was developed to experiment with the algorithms in . RIP was used as the starting point for the development because an implementation was available and distance vector algorithms are simple, as compared to link-state algorithms . In addition, to allow experiments to traverse networks that do not support multicasting, a mechanism called "tunneling" was developed.
The multicast forwarding algorithm requires the building of trees based on routing information. This tree building needs more state information than RIP is designed to provide, so DVMRP is much more complicated in some places than RIP. A link-state algorithm, which already maintains much of the state needed, might prove a better basis for Internet multicasting routing and forwarding.
Waitzman, Partridge & Deering [Page 1]
RFC 1075 Distance Vector Multicast Routing Protocol November 1988
DVMRP differs from RIP in one very important way. RIP thinks in terms of routing and forwarding datagrams to a particular destination. The purpose of DVMRP is to keep track of the return paths to the source of multicast datagrams. To make explanation of DVMRP more consistent with RIP, the word "destination" is used instead of the more proper "source", but the reader must remember that datagrams are not forwarded to these destinations, but originate from them.
This memo is organized into the following sections: - A description of DVMRP is presented. - Tunnels are explained. - The routing algorithm is shown. - The forwarding algorithm is shown. - The various time values are listed. - Configuration information is specified.
This memo does not analyze distanc...