From: Ulrich Weber <uweber@astaro•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: Ulrich Weber <ulrich.weber@googlemail•com>,
David Miller <davem@davemloft•net>,
netdev@vger•kernel.org
Subject: Re: [RFC PATCH] dont create cached routes from ARP requests
Date: Fri, 24 Sep 2010 17:38:48 +0200 [thread overview]
Message-ID: <4C9CC608.7010401@astaro.com> (raw)
In-Reply-To: <1285342083.2503.252.camel@edumazet-laptop>
Yes, as I wrote before my Cable ISP is flooding me with
ARP requests from 10.0.0.0/8, which get a route
via the primary PPP link.
I know thats not a common setup but why do that
kind of routes have to be cached ? :)
steps to reproduce:
server:
ip route add 1.0.0.0/8 dev dummy0
client:
ip route add 1.0.0.0/8 dev eth0
nmap --min-rate 500 -sP 1.0.0.0/8
On 09/24/2010 05:28 PM, Eric Dumazet wrote:
> Le vendredi 24 septembre 2010 à 17:00 +0200, Ulrich Weber a écrit :
>> Hi Eric,
>>
>> please find the output in the attached text file.
>>
>> Neighbor garbage collection wont't work because all
>> neighbor records are bound to cached routes.
>>
>> Forced route garbaged collections returns without freeing
>> any routes, probably because the route threshold is quite high
>> with 65536 compared to the small neighbor threshold of 1024,
>> resulting in a fixed amount of 1024 cached routes...
>>
>> Instead of running the garbage collection we could flush the route
>> cache completely if the neighbor cache overflows.
>> But why do we have to cache that routes in first place ?
>> See the previous patch which skips caching for that kind of routes.
>
> What are the packets you receive ? A flood of ARP answers ?
>
> a "tcpdump -X" of a few packets would help to understand.
>
>
>
--
Ulrich Weber | uweber@astaro•com | Software Engineer
Astaro GmbH & Co. KG | www.astaro.com | Phone +49-721-25516-0 | Fax –200
An der RaumFabrik 33a | 76227 Karlsruhe | Germany
next prev parent reply other threads:[~2010-09-24 15:38 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-22 16:22 [RFC PATCH] dont create cached routes from ARP requests Ulrich Weber
2010-09-23 3:34 ` David Miller
2010-09-23 14:47 ` Ulrich Weber
2010-09-23 15:05 ` Eric Dumazet
2010-09-24 15:00 ` Ulrich Weber
2010-09-24 15:28 ` Eric Dumazet
2010-09-24 15:34 ` Eric Dumazet
2010-09-24 15:43 ` Ulrich Weber
2010-09-24 15:38 ` Ulrich Weber [this message]
2010-09-24 16:05 ` Eric Dumazet
2010-09-24 16:40 ` Ulrich Weber
2010-09-24 16:58 ` Eric Dumazet
2010-09-27 13:11 ` Ulrich Weber
2010-09-23 19:04 ` David Miller
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