[e2e] TCP improved closing strategies?

[Fernando Gont]

William Allen Simpson wrote:

> I've been informed that even today, with a more limited TCP activity,
> busy servers cannot wait 2MSL to finish closing.

Not only busy servers. Many systems have reduced the length of the
TIME-WAIT state, no matter how "busy" they are.


> Also, busy caching servers run out of port numbers, and cycle quickly.
> So there's ample opportunity for seemingly duplicate transmissions.
> 
> I've been searching my personal copy of the e2e-interest archives back to
> '98 (the previous years are only on backup somewhere), and haven't found
> anything on improved closing strategies.  Ideas?

Well, you do have "improved *opening* strategies" :-). See page 93 of:
http://www.gont.com.ar/papers/tn-03-09-security-assessment-TCP.pdf

Timestamps can be used to safely recycle the TIME-WAIT state (provided
that timestamps are monotonically-increasing across connections.)

Thanks!

Kind regards,
-- 
Fernando Gont
e-mail: fernando at gont.com.ar || fgont at acm.org
PGP Fingerprint: 7809 84F5 322E 45C7 F1C9 3945 96EE A9EF D076 FFF1