From: David Ahern <dsahern@gmail.com>
To: Ido Schimmel <idosch@idosch.org>, Qiwei Wen <wenqiweiabcd@gmail.com>
Cc: netdev@vger.kernel.org
Subject: Re: Multicast routing: wrong output interface selected unless VRF default route is added
Date: Tue, 23 Jun 2020 19:14:28 -0700 [thread overview]
Message-ID: <891caeb6-9c1f-d79d-caa6-23aba7e4d0c7@gmail.com> (raw)
In-Reply-To: <20200623183835.GA69452@shredder>
On 6/23/20 11:38 AM, Ido Schimmel wrote:
>>
>> My questions are:
>> 1. is fib_lookup supposed to work with multicast daddr? If so, has
>> multicast routing been working for the wrong reason?
yes; it is a quirk with Linux routing. see the code after fib_lookup in
ip_route_output_key_hash_rcu. perf can show you the call chain that gets
to that lookup if you want the details.
>> 2. Why does the addition of a unicast default route affect multicast
>> routing behaviour?
>
> I believe this was discussed in the past. See:
> https://lore.kernel.org/netdev/20200115191920.GA1490933@splinter/#t
>
prev parent reply other threads:[~2020-06-24 2:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-21 23:19 Multicast routing: wrong output interface selected unless VRF default route is added Qiwei Wen
2020-06-23 18:38 ` Ido Schimmel
2020-06-24 2:14 ` David Ahern [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=891caeb6-9c1f-d79d-caa6-23aba7e4d0c7@gmail.com \
--to=dsahern@gmail.com \
--cc=idosch@idosch.org \
--cc=netdev@vger.kernel.org \
--cc=wenqiweiabcd@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.