Re: [PATCH net-next 1/2] tcp: remove per-destination timestamp cache

Hi David,

On Wed, Mar 15, 2017 at 03:40:44PM -0700, David Miller wrote:

From: Soheil Hassas Yeganeh <redacted>
Date: Wed, 15 Mar 2017 16:30:45 -0400

quoted

Note that this cache was already broken for caching timestamps of
multiple machines behind a NAT sharing the same address.

That's the documented, well established, limitation of time-wait
recycling.

People who enable it, need to consider this issue.

This limitation of the feature does not give us a reason to break the
feature even further as a matter of convenience, or to remove it
altogether for the same reason.

Please, instead, fix the bug that was introduced.

At least I can say I've seen many people enable it without understanding
its impact, confusing it with tcp_tw_reuse, and copy-pasting it from
random blogs and complaining about issues in production.

I agree that it's hard to arbiter between stupidity and flexibility
though :-/

Regards,
Willy