[Pkg-libvirt-maintainers] Bug#923249: Bug#923249: libvirt0: libvirt sets disable_ipv6 on bridge, entirely breaking internal IPv6 networking

[Ralf Jung]

Hi again,

It turns out that setting disable_ipv6=0 is not enough to regain working IPv6:
Now the RAs from the router arrive at the client, but when the client sends a
neighbor discovery, it never makes its way to the router, so the client cannot
actually communicate via IPv6. I can see the ND packages on vnet2 on the host,
but not on virbr1 (which vnet2 is attached to). Again this is something that
worked just fine before the update.

I have no idea what is preventing the ND packages to be forwarded by the bridge.
I always thought bridges are just switches operating on layer 2, but it seems
that's as from the truth...

Kind regards,
Ralf