Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 20 Jun 2000 20:22:44 -0400
From:      "Louis A. Mamakos" <louie@TransSys.COM>
To:        Julie Elizabeth Schlembach <schlem@owlnet.rice.edu>
Cc:        Garrett Wollman <wollman@khavrinen.lcs.mit.edu>, freebsd-net@FreeBSD.ORG
Subject:   Re: Using timestamp option of ip header (IPOPT_TS) 
Message-ID:  <200006210022.UAA27742@whizzo.transsys.com>
In-Reply-To: Your message of "Tue, 20 Jun 2000 13:23:46 CDT." <Pine.GSO.4.21.0006201319150.21983-100000@jungle.owlnet.rice.edu> 
References:  <Pine.GSO.4.21.0006201319150.21983-100000@jungle.owlnet.rice.edu> 

next in thread | previous in thread | raw e-mail | index | archive | help
> 
> >  by reading and writing the option explicitly
> > (IP_RECVOPTS and IP_OPTIONS).
> 
> Thanks for your input so far.  This seems to be what we would like to do -
> how exactly do we go about doing it?  What part of the code needs to be
> modified?  We are using FreeBSD v3.2.
> 

You should really think twice about using this mechanism in any sort
of application that you care about.  Most routers which are used on
the global Internet are optimized for forwarding "normal" traffic at
very high rates of speed and completely insane packet-per-second forwarding
rate.  

Processing the record route with timestamp IP option (and source route) will
cause the packet to generally not be forwarded along the highly optimized
(and in most cases, hardware assisted) path, but to be faulted up to
a CPU to be processed as an exception in a the "slow" path.

There are other mechanisms available to capture a timestamp of when
the packet was received on the local FreeBSD box if that's the
timestamp you're concerned with.

louie




To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-net" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200006210022.UAA27742>