[Spread-users] spread-5.0.0rc1 : data_link.c : algorithm to choose interface(s) for multicast binding changed ?

[Martin Schu]

Hi John,

we have some strange observation:
With spread-4.4.0 running on some of our hosts we see a wrong binding of an
additional interface for multicast, which makes no sense to us and might be
causing problems due to wrong routed traffic.
With spread-5.5.0rc1 this malfunction is gone. Only the correct interface
is bound.

Maybe you can help us to understand what is happening here. Below is the
output of netstat -g on the same host with same configuration. Only the
spread installation was updated! No other change.

Any advice is greatly welcome. We don't understand what causes that wrong
interface binding.

Best regards,
Martin

** spread.conf:
Spread_Segment  239.192.2.2:8982 {
        host1 155.1.1.1  { 155.1.1.1 }
        host2 155.1.1.2  { 155.1.1.2 }
        host3 155.1.1.3  { 155.1.1.3 }
}
Spread_Segment  239.192.2.4:8982 {
        host4 155.1.1.4 { 155.1.1.4 }
        host5 155.1.1.5 { 155.1.1.5 }
        host6 155.1.1.6 { 155.1.1.6 }
}

** *spread-4.4.0 *running:
$ netstat -g
IPv6/IPv4 Group Memberships
Interface       RefCnt Group
--------------- ------ ---------------------
lo              1      224.0.0.1
eth0            1      224.0.0.1
eth1            1      224.0.0.1
eth2            1      239.192.2.2  *!!!WRONG!!!*
eth2            1      224.0.0.1
eth3            1      239.192.2.2    CORRECT
eth3            1      224.0.0.1
eth4            1      224.0.0.1


** no spread running:

$ netstat -g
IPv6/IPv4 Group Memberships
Interface       RefCnt Group
--------------- ------ ---------------------
lo              1      224.0.0.1
eth0            1      224.0.0.1
eth1            1      224.0.0.1
eth2            1      224.0.0.1
eth3            1      224.0.0.1
eth4            1      224.0.0.1

** *spread-5.0.0rc1 *running:
$ netstat -g
IPv6/IPv4 Group Memberships
Interface       RefCnt Group
--------------- ------ ---------------------
lo              1      224.0.0.1
eth0            1      224.0.0.1
eth1            1      224.0.0.1
eth2            1      224.0.0.1
eth3            2      239.192.2.2  CORRECT
eth3            1      224.0.0.1
eth4            1      224.0.0.1
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