Subject: Re: [Bug 194723] connect() to localhost stalls after 4.9 -> 4.10 upgrade

From: Stephen Hemminger <[email-masked]>
Date: Thu, 16 Mar 2017 09:27:17 -0700

On Wed, 15 Mar 2017 15:30:17 -0700 (PDT)
David Miller <[email-masked]> wrote:

> From: Eric Dumazet <[email-masked]>
> Date: Wed, 15 Mar 2017 14:40:34 -0700
> 
> > Finally time to get rid of buggy tw_recycle, that apparently some
> > distros set to one.  
> 
> It's not buggy, it's just not designed in a way that it can work in
> the presence of NAT.
> 
> So yes, indeed, NO DISTRO SHOULD CHANGE THE VALUE TO "1" by default.
> 
> Is CentOS the only culprit?
> 
> But removing it is unnecessary, people who know what they are doing
> can legitimately enable it if they know that there is no NAT going
> on in their paths.

The bug was reported first on CentOs but the bugzilla entry mentions
the same problem exists on Arch Linux. Ubuntu (and Debian) do not have
the problem. RHEL 7 also ok.

https://bugzilla.kernel.org/show_bug.cgi?id=194723