From: Vladimir Ivaschenko <hazard@francoudi.com>
To: Andi Kleen <ak@suse.de>
Cc: linux-kernel@vger.kernel.org
Subject: Re: sendmsg() leaves Identification field in IP header empty
Date: Wed, 5 Dec 2001 22:22:35 +0200 [thread overview]
Message-ID: <20011205222235.A7572@francoudi.com> (raw)
In-Reply-To: <3C0E6F8B.A6C85AB6@francoudi.com.suse.lists.linux.kernel> <p73d71t8md0.fsf@amdsim2.suse.de>
In-Reply-To: <p73d71t8md0.fsf@amdsim2.suse.de>; from ak@suse.de on Wed, Dec 05, 2001 at 09:04:27PM +0100
Andi Kleen wrote about "Re: sendmsg() leaves Identification field in IP header empty":
>
> In theory the hack from TCP could be ported to UDP too, but I'm not sure if it is
> worth it for WCCP (to be honest I don't know what WCCP is so I cannot assess if
> it's important enough to add a workaround for it)
Andi, thanks a lot for the insight, I will try your suggestions.
WCCP is a Web Cache Communication Protocol; it is used by Cisco
routers to forward traffic to proxies. What is confusing is that
send() generates an ID for packets with DF set, at least when
used in a way like Squid uses it. I briefly checked Squid source
code and didn't find any places where it would disable MTU Path
discovery.
> > Sorry if I'm wrong but I think this is a kernel problem because
> > sendmsg() is a system call. On RH6.2 with 2.2.19 this doesn't happen,
>
> It's strictly not a bug because the RFCs don't require an IPID for !DF.
Ok, an intercompatibility issue. :-)
--
Best Regards
Vladimir Ivaschenko
Certified Linux Engineer (RHCE)
next prev parent reply other threads:[~2001-12-05 20:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <3C0E6F8B.A6C85AB6@francoudi.com.suse.lists.linux.kernel>
2001-12-05 20:04 ` sendmsg() leaves Identification field in IP header empty Andi Kleen
2001-12-05 20:22 ` Vladimir Ivaschenko [this message]
2001-12-05 19:03 Vladimir Ivaschenko
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=20011205222235.A7572@francoudi.com \
--to=hazard@francoudi.com \
--cc=ak@suse.de \
--cc=linux-kernel@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.