Re: [nsp] traceroute and icmp

From: Gert Doering (gert@greenie.muc.de)
Date: Thu Nov 29 2001 - 18:26:32 EST


Hi,

On Thu, Nov 29, 2001 at 03:43:10PM -0500, Scott Morris wrote:
> No. Traceroute is simply program.
>
> Unix and Cisco IOS choose to use a UDP variant of it. Microsoft uses a
> straight ICMP.

Hmmm, you word it as if "ICMP is the right (or 'original') way of doing
it" - it isn't, VJ wrote the Unix version, using UDP.

> Doesn't icmp have it's own traceroute extension, just like echo and
> echo reply, or is that just Cisco adding it on? I remember reading this
> somewhere but I cannot verify this. Anyone know?

IP has a "record route" option that can be set in the header. It's
limited by the maximum length of an IP header, so it can only record
a small number of hops, and is thus not widely used. Also machines
in between have to support it, and not all do.

gert

-- 
Gert Doering
Mobile communications ... right now writing from *Enschede(NL)*
... mobile phone: +49 177 2160221 ... or mail me:  gert@greenie.muc.de



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