PIMDD.CONF(5) File Formats Manual PIMDD.CONF(5)

pimdd configuration file


In many cases you do not need to configure pimdd. It configures itself automatically to forward multicast on all multicast-capable interfaces, i.e., interfaces that have the IFF_MULTICAST flag set. It locates other PIM-DM capable routers directly reachable via those interfaces.
pimdd will not start with less than two enabled virtual interfaces (VIFs). A VIF is either a physical multicast-capable interface or a tunnel. To override the default settings, for example to disable some interfaces from being used, configuration commands may be placed in /etc/pimdd.conf.
The file format is relatively free-form: whitespace (including newlines) is not significant. However, the order of some statements are important, more on this below.
By default, pimdd runs on all multicast capable interfaces. The phyint setting can be used to control this behavior.
address | ifname⟩ [
enable | disable
] [
igmpv2 | igmpv3
] [
] [
The PIM assert mechanism arbitrates the forwarder of multicast when there are more than one router with the same (S,G) pair for a given destination LAN. The winner of an assert is the router with either the best (unicast) protocol distance (called metric preference in the RFC), or the best metric if the distance is the same, or, as a tiebreaker, the highest IP address. The loser of an asser election prunes its outbound interface from forwarding and starts an assert timer, in case the active forwarder is lost. The assert-timeout can be used to tune the PIM assert timer to a value between 5 to 210 seconds, default: 180 sec.
The default-route-distance option has nothing to do with the system default route, it is rather the default value for the unicast routing protocol's administrative distance. It is used in PIM Assert elections to determine upstream routers. Currently pimdd.conf cannot obtain the admin distance and metric from the unicast routing protocols, so a default routing protocol distance (the RFC confusingly refers to this as metric prefererence) may be configured. In a PIM Assert election, the router advertising the lowest assert preference will be selected as the forwarder and upstream router for the LAN. Setting 101 should be sufficiently high so that asserts from Cisco or other routers preferred over pimdd.conf.
It is recommended that distances be set such that metrics are never consulted. However, default routing metrics may also be set using the default-route-metric option. (Again, this has nothing to do with the system default route.) This item sets the cost for sending data through this router. You want only PIM-DM data to go to this daemon; so once again, a high value is recommended to prevent accidental usage. The preferred default value is 1024. Both defaults can be overridden per phyint, so learned routes, or PIM Asserts use the phyint's values.
Please also note that PIM Assert elections are not the same as the DR election. The PIM Assert election determines the active multicast forwarder, whereas the DR election determines the active PIM router.
The phyint setting refers to a physical interface and must come after the default-route-metric and default-route-distance settings in the configuration file. Select the interface by its IP address or name. If you just want to activate this interface with default values, you don't need to put anything else on the line. However, there are some additional settings:
Add one phyint line per interface on this router. Otherwise pimdd.conf will run on all interfaces using default settings.

Main configuration file.

pimdd(8), pimctl(8)

This manual page was written by Joachim Wiberg ⟨mailto:troglobit@gmail.com⟩.
August 28, 2021 Debian