From: Stephen Hemminger <stephen@networkplumber.org>
To: David Ahern <dsahern@kernel.org>
Cc: Aleksey Shumnik <ashumnik9@gmail.com>,
netdev@vger.kernel.org, waltje@uwalt.nl.mugnet.org,
Jakub Kicinski <kuba@kernel.org>,
gw4pts@gw4pts.ampr.org, kuznet@ms2.inr.ac.ru,
"willemdebruijn.kernel@gmail.com"
<willemdebruijn.kernel@gmail.com>,
gnault@redhat.com
Subject: Re: [BUG] Dependence of routing cache entries on the ignore-df flag
Date: Fri, 5 May 2023 08:00:14 -0700 [thread overview]
Message-ID: <20230505080014.67bdd6cb@hermes.local> (raw)
In-Reply-To: <20230505031043.GA4009@u2004-local>
On Thu, 4 May 2023 21:10:43 -0600
David Ahern <dsahern@kernel.org> wrote:
> On Wed, May 03, 2023 at 11:35:28AM -0700, Stephen Hemminger wrote:
> > On Wed, 3 May 2023 18:01:03 +0300
> > Aleksey Shumnik <ashumnik9@gmail.com> wrote:
> >
> > > Might you answer the questions:
> > > 1. How the ignore-df flag and adding entries to the routing cache is
> > > connected? In which kernel files may I look to find this connection?
> > > 2. Is this behavior wrong?
> > > 3. Is there any way to completely disable the use of the routing
> > > cache? (as far as I understand, it used to be possible to set the
> > > rhash_entries parameter to 0, but now there is no such parameter)
> > > 4. Why is an entry added to the routing cache if a suitable entry was
> > > eventually found in the arp table (it is added directly, without being
> > > temporarily added to the routing table)?
> >
> > What kernel version. The route cache has been completely removed from
> > the kernel for a long time.
>
> These are exceptions (fib_nh_exception), not the legacy routing cache.
I tried to reproduce your example, and did not see anything.
Could it be the multicast routing daemon (pimd) is watching and adding
the entry?
next prev parent reply other threads:[~2023-05-05 15:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-03 15:01 [BUG] Dependence of routing cache entries on the ignore-df flag Aleksey Shumnik
2023-05-03 18:35 ` Stephen Hemminger
2023-05-03 23:39 ` Aleksey Shumnik
2023-05-05 3:10 ` David Ahern
2023-05-05 15:00 ` Stephen Hemminger [this message]
2023-05-05 15:22 ` David Ahern
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