The DVMRP statement is used to configure DVMRP. GateD-5.0 is compliant with the DVMRPv3 spec.
DVMRP is the original IP Multicast routing protocol. It was designed to run over both multicast capable lans (like Ethernet) as well as through non-multicast capable routers. In this case, the IP Multicast packets are "tunneled" through the routers as unicast packets. This replicates the packets and has an effect on performance, but has provided an intermediate solution for IP Multicast routing on the Internet while router vendors decide to support native IP Multicast routing.
DVMRP has both "tree construction" and "route" passage functions. The DVMRP "routes" are loaded into the multicast RIB under import policy and exported using export policy.
dvmrp ( yes | no | on | off | routing-only ) { interface interface_list { enable | disable | routing-only ; nodvmrpout ; noretransmit ; metric metric ; }; traceoptions trace_options ; }
The dvmrp statement enables or disables the DVMRP protocol. If the dvmrp statement is not specified, the default is dvmrp off. If enabled, DVMRP will default to enabling all interfaces that are multicast capable. dvmrp routing-only specifies that DVMRP will be used only to propagate the multicast RIB, but that it will not be used for tree construction. This may be used to let DVMRP carry the multicast RIB which is then used by PIM-SM.
The options are as follows:
interface interface_list
Enables or disables DVMRP on this interface or list of interfaces. Currently, the GateD implementation of DVMRP does not detect when there are multiple addresses configured on the same physical interface. It will send DVMRP messages to each logical network. This should be fixed in a future release.
The possible parameters are:
disable
Specifies that DVMRP packets received via the specified interface will
be ignored. The default is to listen to DVMRP on all multicast-capable
interfaces.
enable
This is the default. This argument may be necessary when disable
is used on a wildcard interface descriptor.
routing-only
Specifies that the DVMRP routing table will be propagated over the specified
interfaces, but that it is not the multicast routing protocol which will
be used for tree construction. This may be used to let DVMRP carry the
multicast RIB which is then used by PIM-SM.
nodvmrpout
Specifies that no DVMRP packets will be sent on the specified interfaces.
noretransmit
Disables Prune retransmission on the specified interfaces.
metric
This command provides a way to configure the metric on a physical port
or tunnel. This metric will be added to all routes that are learned via
this interface.
traceoptions trace_options Specifies the tracing options for DVMRP. (See Trace Statements and the DVMRP specific tracing options below.) Packet tracing options (which may be modified with detail, send, or recv): packets All DVMRP packets. probe DVMRP Router Probe packets report DVMRP Route Report packets mapper DVMRP Neighbor and Neighbor 2 packets prune DVMRP Prune packets graft DVMRP Graft and Graft Ack packets