Re: [Bridge] [RFC 0/5] bridge - introduce via_phys_dev feature

[Stephen Hemminger <shemminger@linux-foundation.org>]

On Fri, 26 Feb 2010 20:39:59 +0300
Pavel Emelyanov <xemul@openvz.org> wrote:

> Cyrill Gorcunov wrote:
> > On Fri, Feb 26, 2010 at 08:18:43AM -0800, Stephen Hemminger wrote:
> >> Looking back at this. What if the API was simpler:
> 
> Thanks for the reply, Stephen!
> 
> >> Why not:
> >>   1. Setup bridge (and any other interfaces except eth0); includes bringing br0 up
> >>   2. Add eth0 to bridge with new flag to inherit
> >>        a. brctl addif br0 eth0 inherit
> >>
> >> Inherit functionality would need to move address (Ether, IP, IPv6)
> >> and routes from eth0 to br0.
> >> I will see about doing it as much as possible in userspace.
> >>
> 
> Solution is good, but we'll have to reconfigure netfilter matches
> that check for device name/ifindex and restore all this back when
> deleting eth0 from br0.

Netfilter is outside of this, and can't really migrate easily.

> Maybe it's better to implement it on the kernel side by sending a 
> netdev notification and letting the subsystem reconfigure themselves?
> 
> And what can we do with existing TCP connections bound to a device?
> 

TCP connections are never really bound to device. TCP routing is
flexible; if packets can get through, it doesn't care.

--