Re: [PATCH] iplink: add macvlan options for bridge mode

[Arnd Bergmann <arnd@arndb.de>]

Ping!

Stephen, I submitted this twice but never heard back from you.
The changes to macvlan have been merged in 2.6.33-rc1, so it
would be good to have this included as well.

	Arnd

On Tuesday 17 November 2009, Arnd Bergmann wrote:
> Macvlan can now optionally support forwarding between its
> ports, if they are in "bridge" mode. This adds support
> for this option to "ip link add", "ip link set" and "ip
> -d link show".
> 
> The default mode in the kernel is now "vepa" mode, meaning
> "virtual ethernet port aggregator". This mode is used
> together with the "hairpin" mode of an ethernet bridge
> that the parent of the macvlan device is connected to.
> All frames still get sent out to the external interface,
> but the adjacent bridge is able to send them back on
> the same wire in hairpin mode, so the macvlan ports
> are able to see each other, which the bridge can be
> configured to monitor and control traffic between
> all macvlan instances. Multicast traffic coming in
> from the external interface is checked for the source
> MAC address and only delivered to ports that have not
> yet seen it.
> 
> In bridge mode, macvlan will send all multicast traffic
> to other interfaces that are also in bridge mode but
> not to those in vepa mode, which get them on the way
> back from the hairpin.
> 
> The third supported mode is "private", which prevents
> communication between macvlans even if the adjacent
> bridge is in hairpin mode. This behavior is closer to
> the original implementation of macvlan but stricly
> maintains isolation.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>