[Gllug] just preaching to the converted !

[Steve Nelson]

On 10/22/05, Nix <nix at esperi.org.uk> wrote:

> > No, there isn't. Indeed, there never was. At one time, they used the
> > BSD networking code, but it was hardly stolen -- the license explicitly
> > allows for it to be used like that. These days, they've rewritten their
> > IP stack from scratch. AFAIK, the only BSD code left is in the FTP client.
>
> ping? tracert (ick)?

I'm pretty confident tracert is Microsoft's own....

BSD traceroute sends a trio of UDP datagrams with increasing TTL
values.  The idea being that nodes/routers en route will reply with an
ICMP Time Exceed packet until the host is reached, at which point it
will elicit an ICMP Port Unreachable.

Microsoft reckoned this approach was flawed at two levels - firstly,
we cannot be sure that high UDP ports are not actually being used, and
secondly, its probably not unlikely that UDP will be filtered. 
Consequently their tracert sends ICMP Echo Request packets, expecting
ICMP Echo Reply.

Sun's traceroute allows you to specify which method to use, using the
-I switch to use ICMP instead of the default UDP behaviour.

S.
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