From: Stephen Hemminger <stephen.hemminger@vyatta.com>
To: Eugene Teo <eugeneteo@kernel.sg>
Cc: netdev@vger.kernel.org, Eugene Teo <eteo@redhat.com>
Subject: Re: Internet-Draft on Port Randomisation
Date: Mon, 08 Sep 2008 21:58:44 -0700 [thread overview]
Message-ID: <48C60284.2070402@vyatta.com> (raw)
In-Reply-To: <28fa9c5e0809082107p7a33dc4fod344fde212e1d710@mail.gmail.com>
Eugene Teo wrote:
> Has anyone read this Internet-Draft?
> http://www.gont.com.ar/drafts/port-randomization/draft-ietf-tsvwg-port-randomization-02.txt
>
> In this memo, there are descriptions of four different ephemeral port
> randomisation algorithms (see page 17).
>
> Algo #1 and #2 are simple port randomisation algorithms. Algo #3 is
> what we have in Linux. The memo suggested algorithm #4, double-hash
> randomisation algorithm, which is an improvement to algo #3 (see page
> 15).
>
> Does anyone have any thought about the improved algorithm? Is this
> worth implementing,
No the added lock overhead of a global next free port array is not worth
it. Think of big web server under
DoS pressure. The existing port search can run in parallel, Algo #4 was
suggested by people
who don't work on a real SMP OS.
next prev parent reply other threads:[~2008-09-09 4:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-09 4:07 Internet-Draft on Port Randomisation Eugene Teo
2008-09-09 4:58 ` Stephen Hemminger [this message]
2008-09-09 6:31 ` Eugene Teo
2008-09-09 14:28 ` Andi Kleen
2008-09-09 20:04 ` David Miller
2008-09-09 20:11 ` Andi Kleen
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=48C60284.2070402@vyatta.com \
--to=stephen.hemminger@vyatta.com \
--cc=eteo@redhat.com \
--cc=eugeneteo@kernel.sg \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.