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

pimd.conf —
pimd configuration file

/etc/pimd.conf

In many cases you do not need to configure pimd. 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-SM/SSM capable routers directly reachable via those interfaces.
pimd 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/pimd.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.
All <len> arguments to an IPv4 address, group or network can also be given in the alternative /CIDR format. E.g., <group>/<len>.
By default, pimd runs on all multicast capable interfaces. The optional no phyint setting and the phyint setting can be used to control this behavior. More on the phyint interface configuration setting below.
<1-255>
This option has nothing to do with the system default route. It is the default value for the unicast routing protocol's administrative distance. It is used in PIM Assert elections to determine upstream routers. Currently pimd cannot obtain the admin distance and metric from the unicast routing protocols, so a default routing protocol distance may be configured. The RFC confusingly refers to this as metric prefererence. 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 GateD routers are preferred over poor-little pimd.
It is recommended that distances be set such that metrics are never consulted.
<1-1024>
This setting control the default routing metrics. Again, this has nothing to do with the system default route. This item sets the default cost for sending data through this router. You want only PIM-SM 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 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.
<1-65535>
This setting controls the interval between IGMP querys (QI). It is used only when acting as the elected IGMP querier on a LAN. In IGMP the lowest numerical address on the LAN becomes the elected querier. This value must be same across all IGMP capable devices on the same LAN! Including any IGMP snooping switches (bridges) that can act as IGMP querier.
The query response interval (QRI) is hard-coded to 10 seconds, so in practice, the query interval should not be less than that. Also, at startup pimd.conf sends the first queries at a quicker interval (QI / 4) to speed up inital convergence.
Default value, per RFC2236: 125
<8-65535>
This setting controls the amount of time that pimd must wait to determine any previous IGMP querier (multicast router) has been lost. RFC2236 calls this the "Other Querier Present Interval" and recommends it be set to a robustness value times the query interval, plus half the query response time. The pimd robustness value for IGMP is 3 and the default query response time is 10 sec. This value must be same across all IGMP capable devices on the same LAN! Including any IGMP snooping switches (bridges) that can act as IGMP querier.
Default value, per RFC2236: 380
<30-18724>
The PIM Hello message interval can be tuned by changing this setting. It also affects the hold-time value included in Hello messages. The hold-time value is 3.5 times hello-interval. Anything less than 30 sec is considered an "aggressive" setting and is unsupported.
Default value: 30 sec.
This setting controls if pimd should start up with all multicast-capable interfaces as enabled or disabled. For more information, see the description of phyint, below.
<address | ifname> [
disable | enable
] [
igmpv2 | igmpv3
] [
dr-priority <1-4294967294>
] [
ttl-threshold <1-255>
] [
distance <1-255>
] [
metric <1-1024>
] [
altnet network/len | network masklen len
] [
scoped network/len | network masklen len
]
This setting selects and alters properties of the phyiscal interfaces pimd operates on. Interfaces can be identified using their local IP address or their name.
NOTE: All phyint commands must come after the default-route-metric and default-route-distance settings in the configuration file.
|
Selectively disable or enable this interface. Only enabled interfaces get a VIF in the kernel.
|
Force interface to use IGMPv2 or IGMPv3. Default: igmpv3 since v2.3.0.
<1-4294967294>
When there are multiple PIM routers on the same LAN the DR is usually elected based on the highest numerical IP address. This setting can be used to control the DR Priority option in PIM Hellow messages, which by default otherwise is 1. When the DR Priority option is advertised by all PIM routers on the same LAN the highest priority router wins the DR election, regardless of its IP. If any router does not advertise the DR Priority option, or the same priority is advertised by more than one router, the protocol falls back to using the IP address.
<1-255>
The TTL threshold for multicast frames to be forwarded from this interface. Useful for defining boundaries for local, site, and global multicast. This is often referred to as TTL scoping. Default: 1
<1-255>
Use this to override the default-route-distance (101) on this phyint in PIM Assert elections.
<1-1024>
The cost of sending data through this interface. Defaults to default-route-metric (1024) if not assigned.
<network/len>
Alternative host(s)/network(s) to accept as locally attached multicast sources on a given interface. If a phyint is attached to multiple IP subnets, describe each additional subnet with the altnet keyword.
<network/len>
Optional scoping of multicast groups. This allows interfaces to be configured as an administrative boundary for the specified group(s). Multicast streams belonging to the scoped groups will not be forwarded.
[
address | ifname
] [
priority <0-255>
]
The bsr-candidate (CBSR) setting is enabled in the default configuration file. It can be disabled by commenting it out, but make sure at least one bootstrap router (BSR) is available in the network.
|
Optional local IPv4 address, or interface name to acquire address from. If both address and ifname is left out, pimd will default to the highest active IP address.
<0-255>
How important this router is compared to others. A larger numeric value denotes higher priority, c.f. rp-candidate where it's the reverese.
[
address | ifname
] [
priority <0-255>
] [
interval <10-16384>
] [
group-prefix group/len | masklen len
]
The rp-candidate (CRP) setting is enabled in the default configuration file. It can be disabled by commenting out the line, but make sure there is at least one Rendez-vous Point (RP) in the network for PIM-SM. See rp-address (below) for how to configure a static RP.
|
Optional local IPv4 address, or interface name to acquire address from. If both address and ifname is left out, pimd will default to the highest active IP address.
<0-255>
A smaller numeric value denotes higher priorty, c.f. bsr-candidate where it's the reverse. If the priority is omitted pimd and Cisco IOS default to 0, the standard says 192 for RP.
<10-16383>
The advertisement interval in seconds for this CRP. The default value is 30 seconds. Use a lower value for faster convergence.
[
[
group/len
] | [
group masklen len
]
]
The group-prefix option is the set of multicast groups that the CRP will advertise to other routers, if it wins an election:
group/len
A specific multicast group, or network range in CIDR syntax this router will handle.
group masklen len
Optional number of groups, in prefix length format. Remember that a multicast address is a Class D and has a netmask of 240.0.0.0, which means its length is 4.
Multiple lines of group-prefix may be given, but the maximum number of records supported in pimd is 255.
address [
group-addr/len | group-addr masklen len
]
This setting is for static rendezvous point (RP) configurations. It defines the RP for a given group, or range of groups. The argument can be either a unicast address or a multicast group, with an optional group address and netmask. Default group and netmask is 224.0.0.0/16. Note: all static RP's are announced with priority 1 (second highest, see above).
[
rate KBPS | packets NUM | infinity
] [
interval SEC
]
This replaces two previous configuration settings: switch_data_threshold and switch_register_threshold. It controls the switch-over from the shared tree to the shortest-path source tree. The default is to do the switch-over after the first packet, but only after 100 seconds. If infinity is specified the shortest path switch-over is disabled.

/etc/pimd.conf
Main configuration file.

pimd(8), pimd-dense(8), pimctl(8)

This manual page was written by Joachim Wiberg ⟨mailto:troglobit@gmail.com⟩.
October 17, 2020 Debian