Firewalld, IPv6, no forwarding happening

[Richard W.M. Jones]

It turns out there are two problems.

(1) You must manually assign a public IPv6 address to at least one of
your router's interfaces.  This is because when sending an IPv6
packet, the kernel chooses a source address by looking at the
addresses of all interfaces.  If none of them has a public address, it
chooses some link local address as the source address, and of course
that's never going to work.

To do this, add an IPV6ADDR=... entry to
/etc/sysconfig/network-scripts/ifcfg-<some_interface>

That should be enough to get ping working.

(2) Firewalld filters all forwarded IPv6 packets.  This appears to be
a massive bug, or at least it's a completely undocumented limitation.

https://bugzilla.redhat.com/show_bug.cgi?id=929426

The workaround can be found in that bug.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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