The multicast statement is used to set interface-specific options such
as rate limits, TTL thresholds, and admin scope boundaries (admin scope
boundaries are not yet implemented).
GateD-5.0 also supports static group memberships on interfaces. These can be used to manually configure tree branches, and can be used regardless of whether a multicast routing protocol is configured on the relevant interface.
Static joins and scoped boundaries are configured by commands inside the "multicast {}" block. The new syntax for the multicast block is:
multicast { interface interface_list [threshold number] [ratelimit number]; join network [(mask mask) | (masklen number)] interface_list; boundary network [(mask mask) | (masklen number)] interface_list; }
Example:
multicast { interface le1 threshold 16 ratelimit 500; join 239.1.2.3 le1; };
The example above configures interface le1 with a TTL threshold of 16, a rate limit on multicast traffic of 500 Kbps, and forces GateD to believe that downstream members of group 239.1.2.3 exist on that interface.
Example:
multicast { interface le1 threshold 16 ratelimit 500; boundary 239.255.0.0 masklen 16 le1; };
The example above configures interface le1 with a TTL threshold of 16, a rate limit on multicast traffic of 500 Kbps, and sets a boundary for 239.255/16 on it.
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