netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Ahern <dsahern@gmail.com>
To: Ido Schimmel <idosch@idosch.org>, Ben Greear <greearb@candelatech.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: vrf and multicast is broken in some cases
Date: Wed, 15 Jan 2020 13:33:41 -0700	[thread overview]
Message-ID: <9ed604cd-19de-337a-e112-96e05dad1073@gmail.com> (raw)
In-Reply-To: <20200115202354.GB1513116@splinter>

On 1/15/20 1:23 PM, Ido Schimmel wrote:
> 
> I'm not sure this is the correct way (David?). Can you try to delete
> this default route and instead add a default unreachable route with an
> high metric according to step 3 in Documentation/networking/vrf.txt:
> 
> "
> 3. Set the default route for the table (and hence default route for the VRF).
>        ip route add table 10 unreachable default metric 4278198272
> 
>    This high metric value ensures that the default unreachable route can
>    be overridden by a routing protocol suite.  FRRouting interprets
>    kernel metrics as a combined admin distance (upper byte) and priority
>    (lower 3 bytes).  Thus the above metric translates to [255/8192].
> "
> 
> If I'm reading ip_route_output_key_hash_rcu() correctly, then the error
> returned from fib_lookup() because of the unreachable route should allow
> you to route the packet via the requested interface.
> 

yes, IPv4 is a bit goofy with multicast (at least to me, but then I have
not done much with mcast).

  reply	other threads:[~2020-01-15 20:33 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-15 17:57 vrf and multicast is broken in some cases Ben Greear
2020-01-15 18:45 ` David Ahern
2020-01-15 19:02   ` Ben Greear
2020-01-15 19:19     ` Ido Schimmel
2020-01-15 20:00       ` Ben Greear
2020-01-15 20:23         ` Ido Schimmel
2020-01-15 20:33           ` David Ahern [this message]
2020-01-15 21:09             ` Ben Greear
2020-01-15 22:53               ` David Ahern
2020-01-15 20:24         ` David Ahern

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=9ed604cd-19de-337a-e112-96e05dad1073@gmail.com \
    --to=dsahern@gmail.com \
    --cc=greearb@candelatech.com \
    --cc=idosch@idosch.org \
    --cc=netdev@vger.kernel.org \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).