Re: [net-next PATCH] net: RFC3069, private VLAN proxy arp support

[Jesper Dangaard Brouer <hawk@comx.dk>]

On Wed, 2010-01-06 at 23:22 +1030, Mark Smith wrote:
> On Wed, 06 Jan 2010 10:49:29 +0100
> Jesper Dangaard Brouer <hawk@comx.dk> wrote:
> > 
> > This patch solved the issue by doing proxy arp'ing on the router against
> > the "local" network, thus making it possible for customers to
> > communicate, but via the router.  This also gives the ability to do
> > firewalling on the router between customers on an Ethernet. (In our
> > solution the Linux router also have a personal firewall configurable per
> > customer.)
> > 
> 
> I can see value in that - you're forcing all traffic through the
> upstream router for policy enforcement purposes, without having to have
> point-to-point (simulated or otherwise) links between customers and the
> router, and avoiding IP address waste by not using /30s. You're pretty
> much making the ethernet a Non-broadcast Multi-Access link.

Yes, its actually a quite nice trick, and several switch vendors have
supported this technology for years (although they all annoying call it
something differently).  And we/ComX have actually also been using this
for years, including my patch (sorry for being so slow with upstream
submission).

-- 
Med venlig hilsen / Best regards
  Jesper Brouer
  ComX Networks A/S
  Linux Network Kernel Developer
  Cand. Scient Datalog / MSc.CS
  Author of http://adsl-optimizer.dk
  LinkedIn: http://www.linkedin.com/in/brouer