Multicast group memberships lost if eth0 brought down and up
Deron Meranda
deron.meranda at gmail.com
Fri Oct 1 16:25:35 UTC 2004
Is this the correct behavior, or a bug? (seeing this in both FC2
as well as EL3)
I wrote an application which registers itself in a couple IPv6
multicast groups on an ethernet interface. A "netstat -A inet6 -g"
then shows the group membership, such as
IPv6/IPv4 Group Memberships
Interface RefCnt Group
--------------- ------ ---------------------
lo 1 ff02::1
eth0 1 ff02::eb42:8740
eth0 1 ff02::f6b6:d980
eth0 1 ff02::1:ff13:7276
eth0 1 ff02::1
If I then leave the application running, but do
an "ifdown eth0" then "ifup eth0", I get this,
IPv6/IPv4 Group Memberships
Interface RefCnt Group
--------------- ------ ---------------------
lo 1 ff02::1
eth0 1 ff02::1:ff13:7276
eth0 1 ff02::1
Are group memberships supposed to be preserved across
up/down cycling? If not, then what's the proper way for an
application to detect that this has occurred so it can re-register?
Note that the app can still successfully SEND packets to the
group, but obviously, it no longer receives any packets.
--
Deron Meranda
More information about the fedora-list
mailing list