Well the traceroute implementation we use around here limits how fast it
sends out probes, to no more than one a second. From your comment I take
it not everyone does this?

Rich

> -----Original Message-----
> From: Pekka Savola [mailto:[EMAIL PROTECTED]] 
> Sent: Monday, October 29, 2001 10:24 PM
> To: Richard Draves
> Cc: Lori Napoli; [EMAIL PROTECTED]
> Subject: RE: ICMPv6 rate limiting factor
> 
> 
> On Mon, 29 Oct 2001, Richard Draves wrote:
> > The Microsoft implementation limits to two errors per 
> second, just for 
> > this reason.
> 
> That is only good enough if you assume the tracerouter is 
> over 500ms away, 
> because traceroute by default sends out three probes..
> 
> I've commented on the new ICMP draft that this issue should 
> be taken into consideration, and apparently it will, as the 
> draft didn't progress at IETF51.
> 
> B.t.w. Linux uses a token bucket mechanism here and is not affected.
> 
> B.t.w.2. Cisco implementation is(/was) also broken, another 
> issue I mentioned here and on [EMAIL PROTECTED], they promised 
> they'd be working on it.
> 
> > > -----Original Message-----
> > > From: Lori Napoli [mailto:[EMAIL PROTECTED]]
> > > Sent: Monday, October 29, 2001 6:59 PM
> > > To: [EMAIL PROTECTED]
> > > Subject: ICMPv6 rate limiting factor
> > > 
> > > 
> > > RFC 2463 states that it is a MUST to limit the rate of ICMPv6
> > > error messages that are sent.  Traceroute is a utility that 
> > > relies on ICMP error messages.  One of the parameters for 
> > > traceroute is the number of probes
> > > that are sent for each hopcount.   RFC 2463 gives an example 
> > > of 1 second as
> > > a conservative default if timer based rate limiting was 
> > > implemented.   If
> > > this is used,  traceroute won't receive a reply for each 
> > > probe if multiple probes are sent for each hopcount since 
> > > some will be supressed due to the rate limiting factor.  What 
> > > are other implementations doing in regard to ICMPv6 rate limits?
> > > 
> > > Thanks
> > > Lori
> > > 
> > > 
> > > 
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> -- 
> Pekka Savola                 "Tell me of difficulties surmounted,
> Netcore Oy                   not those you stumble over and fall"
> Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords
> 
> 
> 
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