Re: ipv6 global forward overrides dev-specific forwarding

[kuznet@xxxxxxxxxxxxx]

Hello!

> It seems senseless for it to behave this way.

Per-device enabling/disabling forwarding in IPv6 simply does not exist.
This switch is global only: either the whole node is router or it is not
a router. Per-device "forwarding" switch controls only
autoconfiguration/ndisc aspects.

In IPv4 it was possible because it is able to make routing decisions
based on input interface. IPv6 is not. It is easy to add direct
check of the flag to ip6_forward, but I see no reasons to do this
as soon as the feature is not obtained for no fee (like ip).

If someone wants to control forwarding per-device, this can be made
with a netfilter rule. The same is with IP. And f.e. if we were able
to kill policy routing, per-device forwarding switch would stop to work
as well.

Alexey