From: Hannes Frederic Sowa <hannes@stressinduktion.org>
To: David Miller <davem@davemloft.net>, jkbs@redhat.com
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 0/5] Route ICMPv6 errors with the flow when ECMP in use
Date: Thu, 27 Oct 2016 23:54:49 +0200 [thread overview]
Message-ID: <b68ce770-4035-e2db-3df2-4cbe83cc20be@stressinduktion.org> (raw)
In-Reply-To: <20161027.112331.1872860838376990837.davem@davemloft.net>
Hi,
On 27.10.2016 17:23, David Miller wrote:
> From: Jakub Sitnicki <jkbs@redhat.com>
> Date: Mon, 24 Oct 2016 11:28:47 +0200
>
>> However, for it to work IPv6 flow labels have to be same in both
>> directions (i.e. reflected) or need to be chosen in a manner that
>> ensures that the flow going in the opposite direction would actually
>> be routed to a given path.
>
> My understanding is that this is not really guaranteed, and that
> entities are nearly encouraged to set the flow label in whatever
> manner makes sense for their use case.
In general this is true.
> I think we really cannot have any kind of hard dependency on how
> flow labels are set and used by the internet.
Probably/Hopefully ECMP setups are set up by the same entity that also
operates the servers, thus they can easily control the reflection of
flow labels on those servers. This might be especially important for
anycast services hosted behind ECMP services.
If the flow labels don't match, these patches are just best effort and
don't improve nor worsen the situation (lot's of traffic afaik still
carries 0 as flow label which indeed does help).
Bye,
Hannes
prev parent reply other threads:[~2016-10-27 21:54 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-24 9:28 [PATCH net-next 0/5] Route ICMPv6 errors with the flow when ECMP in use Jakub Sitnicki
2016-10-24 9:28 ` [PATCH net-next 1/5] ipv6: Fold rt6_info_hash_nhsfn() into its only caller Jakub Sitnicki
2016-10-24 9:28 ` [PATCH net-next 2/5] net: Extend struct flowi6 with multipath hash Jakub Sitnicki
2016-10-24 9:39 ` Hannes Frederic Sowa
2016-10-24 9:28 ` [PATCH net-next 3/5] ipv6: Use multipath hash from flow info if available Jakub Sitnicki
2016-10-24 9:40 ` Hannes Frederic Sowa
2016-10-24 9:28 ` [PATCH net-next 4/5] ipv6: Compute multipath hash for sent ICMP errors from offending packet Jakub Sitnicki
2016-10-24 9:40 ` Hannes Frederic Sowa
2016-10-27 15:24 ` David Miller
2016-10-27 22:00 ` Jakub Sitnicki
2016-10-24 9:28 ` [PATCH net-next 5/5] ipv6: Compute multipath hash for forwarded " Jakub Sitnicki
2016-10-24 9:43 ` Hannes Frederic Sowa
2016-10-27 15:25 ` David Miller
2016-10-27 22:10 ` Jakub Sitnicki
2016-10-27 22:35 ` Tom Herbert
2016-10-28 8:32 ` Jakub Sitnicki
2016-10-28 14:25 ` Tom Herbert
2016-10-30 13:03 ` Jakub Sitnicki
2016-10-31 19:15 ` David Miller
2016-11-01 15:13 ` Jakub Sitnicki
2016-11-01 15:35 ` David Miller
2016-11-01 16:26 ` Jakub Sitnicki
2016-11-01 16:27 ` Hannes Frederic Sowa
2016-11-01 16:39 ` David Miller
2016-11-01 16:59 ` Hannes Frederic Sowa
2016-10-31 19:25 ` Tom Herbert
2016-11-01 15:43 ` Jakub Sitnicki
2016-11-01 16:25 ` Hannes Frederic Sowa
2016-11-01 16:39 ` Tom Herbert
2016-11-01 16:54 ` Hannes Frederic Sowa
2016-10-27 15:23 ` [PATCH net-next 0/5] Route ICMPv6 errors with the flow when ECMP in use David Miller
2016-10-27 21:54 ` Hannes Frederic Sowa [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=b68ce770-4035-e2db-3df2-4cbe83cc20be@stressinduktion.org \
--to=hannes@stressinduktion.org \
--cc=davem@davemloft.net \
--cc=jkbs@redhat.com \
--cc=linux-kernel@vger.kernel.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).