[Xorp-hackers] multicast source filter API in linux

[Sachin K]

When I set the source filter using the setsockopt() call for the
following scenario
mode: INCLUDE
number of sources: 3
sources: s1, s2, s3
Group: G

The kernel first sends out a TO_EX{} report for G and then a TO_IN{s1,
s2, s3} report for G.

Does anybody know why linux does this?

Thanks,
Sachin