netdev - Re: missing icmp redirects

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Message-ID: <539802FA.3040207@computer.org>
Date:	Wed, 11 Jun 2014 09:19:22 +0200
From:	Per Jessen <per@...puter.org>
To:	Dmitry Popov <ixaphire@...tor.net>
CC:	Lukas Tribus <luky-37@...mail.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: missing icmp redirects

Dmitry Popov wrote:
> On Tue, 10 Jun 2014 20:10:23 +0200
> Per Jessen <per@...puter.org> wrote:
> 
>> Lukas Tribus wrote:
>>>> See complete description here:
>>>>
>>>> https://bugzilla.kernel.org/show_bug.cgi?id=72561
>>>>
>>>> Summary - some ICMP redirects seem to be missing.
>>>>
>> Okay, I have devised a way to reproduce the problem:
>>
>> ...
> 
> It's probably not a bug, but intended behavior. See ip_rt_send_redirect in 
> net/ipv4/route.c. The kernel has a built-in per-source-address limiter for icmp
> redirects. 

Hi Dmitry

Any possibility that this limiter may have been inactive/faulty in e.g. 2.6.34? 
  We only hit this issue when we upgraded the firewall to a newer openSUSE (for 
ebtables) which came with kernel 3.11.6, but prior to that we had no issue with 
missing redirects.

> You can disable it for example with 
> echo -1 > /proc/sys/net/ipv4/route/redirect_silence
> Though I am not sure if it is ok in wild networks.

Okay, that worked on the first attempt.
Should I also be looking at the other redirect settings?

/proc/sys/net/ipv4/route/redirect_load
/proc/sys/net/ipv4/route/redirect_number



thanks
Per
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