Provided by: smcroute_2.5.5-1_amd64 bug


     smcroutectl — Control and status tool for smcrouted(8)


     smcroutectl [-dptv] [-i NAME] [-u FILE] [COMMAND]

     smcroutectl ⟨help | flush | kill | reload | version⟩
     smcroutectl ⟨show⟩ [groups | routes]
     smcroutectl ⟨add  |   rem⟩ IIF [SOURCE] GROUP[/LEN] OIF [OIF ...]
     smcroutectl ⟨join | leave⟩ IIF [SOURCE] GROUP[/LEN]


     smcroutectl is the control tool for smcrouted(8).  It can be used to query status, debug,
     modify the kernel multicast forwarding cache (MFC), manage group interface memberships,
     reload smcroute.conf, and kill a running smcrouted.


     The following smcroutectl options are available:

     -d      Enable detailed output in show commands.

     -i NAME
             Connect to an smcrouted instance that runs with another identity, NAME.

             This option is required for both smcrouted and smcroutectl when running multiple
             smcrouted instances, e.g., when using multiple routing tables, on Linux.

     -p      Use plain table headings in show command output.  No ANSI control characters are
             used, not even for probing screen width.

     -u FILE
             UNIX domain socket path, used for the IPC between smcrouted and smcroutectl.  Use
             this to override the default socket path, otherwise derived from the identity, -i
             NAME.  This option can be useful when overriding the identity is not sufficient,
             e.g. for testing.  The default depends on how smcroutectl is configured at build
             time, see FILES.

     -t      Skip table headings entirely in show command output.


     The IIF and OIF arguments in the below smcroutectl commands are the interface names, or
     interface wildcards of the form eth+, which matches eth0, eth10, etc.  Wildcards are
     available for both inbound and outbound interfaces.

     A multicast route is defined by an input interface IIF, the sender's unicast IP address
     SOURCE, which is optional, the multicast group GROUP and a list of, at least one, output
     interface OIF [OIF ...].

     Please refer to smcrouted(8) for more details on the operation and how ASM/SSM multicast


     Commands can be abbreviated to the minimum unambiguous prefix; for example, s g for show
     groups.  The following commands are available:

     add IIF [SOURCE[/LEN]] GROUP[/LEN] OIF [OIF ...]
             Add a new multicast route the the kernel MFC, or modify the outbound interfaces
             (OIF) an existing route.

             The arguments are, in order: IIF the inbound interface, SOURCE originating IP
             address (may need to be reachable in the unicast routing table to be allowed by the
             kernel reverse-path check), GROUP the multicast group address, and OIF [OIF ...] the
             outbound network interface(s).

             The interfaces provided as IIF and OIF can be any multicast capable network
             interface as listed by ‘ifconfig’ or ‘ip link list’, including tunnel interfaces and
             loopback.  Provided smcrouted has "enumerated" them.  See smcrouted(8), in
             particular the command line option -N, and the smcroute.conf(5) ‘phyint’ directive.

             To add a (*,G) route, either omit the SOURCE argument completely, or set it to
    for IPv4, and if you want to specify a range of groups, use the ‘GROUP/LEN’
             modifier, e.g.  ‘’.

     remove IIF [SOURCE[/LEN]] GROUP[/LEN] [OIF [OIF ...]]
             Remove or modify the outbound interfaces of a multicast route in the kernel MFC.

             When no OIF argument is given, this command removes the entire route.  With one or
             more OIF arguments, each outbound interface listed is removed.  Skipping any
             unmatched or invalid interface names.  When no more outbound interfaces exist, the
             route will have been transformed into a "stop filter".  To remove the route
             entirely, the command must be given with no OIF arguments.

     flush   Flush dynamic (*,G) multicast routes now.  Similar to how -c SEC works in smcrouted,
             this command initiates an immediate flush of all dynamically installed (*,G)
             multicast routes.  Useful when a topology change has been detected and need to be
             propagated to smcrouted.

     join IIF [SOURCE[/LEN]] GROUP[/LEN]
             Join a multicast group, with an optional prefix length, on the given (inbound)
             interface.  The source address is optional, but if given a source specific (SSM)
             join is performed.  Note, joining groups is only ever necessary on the inbound
             interface, never on the outbound.  Unless, two-way routing the same group.

             Note, as mentioned in smcrouted(8), joining a group to open up traffic in layer-2
             network switches is only a workaround to direct multicast towards SMCRoute.  When
             routing lots of traffic it is advised to avoid this mechanism.  Instead, use
             multicast router ports, or similar settings on the switches, or if they support
             multicast router discovery (MRDISC), see RFC4286.

     leave IIF [SOURCE[/LEN]] GROUP[/LEN]
             Leave a multicast group, with optional prefix length, on a given (inbound)
             interface.  As with the join command, above, the source address is optional, but if
             the group was subscribed to with source it must be unsubscribed with source as well.

     help [cmd]
             Print a usage information message.

     kill    Tell a running smcrouted to exit gracefully, same as SIGTERM.

     reload  Tell smcrouted to reload its configuration and activate the changes.  Same as
             SIGHUP.  Note, any routes or groups added or removed with smcroutectl will be lost.
             Only the configuration set in the file smcroute.conf is activated.

     show [groups|routes]
             Show joined multicast groups or multicast routes, defaults to show routes.  Can be
             combined with the -d option to get details for each multicast route.

             Show program version and support information.


     smcrouted(8), smcroute.conf(5)


     SMCRoute was originally created by Carsten Schill <>.  Initial IPv6
     support by Todd Hayton <>.  Initial FreeBSD support by Micha Lenk

     SMCRoute is currently maintained by Joachim Wiberg <>, and Micha Lenk
     <> at GitHub: