Subject: Re: [RFC PATCH] dont create cached routes from ARP requests

From: Ulrich Weber <[email-masked]>
Date: Thu, 23 Sep 2010 16:47:08 +0200

On Wed, Sep 22, 2010 at 08:34:42PM -0700, David Miller wrote:
> From: Ulrich Weber <[email-masked]>
> Date: Wed, 22 Sep 2010 18:22:09 +0200
> 
> > Background: At home I have two Internet connections, DSL and Cable.
> > DSL is the primary uplink while Cable is the secondary.
> > My Cable ISP is flooding me with ARP request from 10.0.0.0/8,
> > which creates routes via the primary uplink.
> > There are thousands of cached routes and after some time
> > I get "Neighbour table overflow" messages.
> 
> If you get neighbour table overflows, something is holding a reference
> to the routing cache entry and/or the neighbour entries those routing
> cache entries are attached to.
> 
> If these really are transient entries, they should be trivially
> garbage collected and not cause any problems at all.
rt_garbage_collect is not called within rt_intern_hash,
because the call is done within softirq context.

Forcing the call of rt_garbage_collect didn't help either,
there are no routes freed afterwards...

Cheers
 Ulrich