Re: [PATCH] ipv6: Fix for adding multicast route for loopback device automatically.

From: Li Wei <redacted>
Date: Thu, 08 Dec 2011 08:58:21 +0800

The problem is that the resulting routing table depends on the sequence
of interface's initialization and in some situation, that would block all
muticast packets. Suppose there are two interfaces on my computer
(lo and eth0), if we initailize 'lo' before 'eth0', the resuting routing
table(for multicast) would be

# ip -6 route show | grep ff00::
unreachable ff00::/8 dev lo metric 256 error -101
ff00::/8 dev eth0 metric 256

When sending multicasting packets, routing subsystem will return the first
route entry which with a error set to -101(ENETUNREACH).

I know the kernel will set the default ipv6 address for 'lo' when it is up
and won't set the default multicast route for it, but there is no reason to
stop 'init' program from setting address for 'lo', and that is exactly what
systemd did.

Ok, I added this more detailed explanation to the commit message and
applied your patch.

Probably it is a good idea to explain things completely, with all details
and examples, in the commit message from the beginning :-)