Re: [Sheflug] (no subject)

["Chris J" <cej [at] xxxxxxxxxxxxxxxx>]

And Lo! The Great Prophet Matthew Collins uttered these words of wisdom:
> On Tue, Sep 30, 2003 at 07:19:37PM +0100, Andy Morris wrote:
> > 
> > what i ,meant to say was that demon and bt block all icmp traffic on there 
> network, and as such ping wont work, you need to use the tracepath command fr
> om within  the sbin directory, as this uses udp
> > 
> 
> Huh? I'm sorry, but you are wrong. I'm a Demon customer, and they have
> never banned ICMP traffic. ping and traceroute work just fine thanks. I
> don't know where you got that idea from. I used to be Dial up, and am
> now ADSL. I use traceroute a lot, and it always works.
> 

I'm a little confused; Andy - by tracepath do you mean traceroute? 
Either way, traceroute on UNIX has always used UDP, so won't be affected
by ICMP blocking. It is stopped by lots of firewalls though, which can 
make it rather awkward. There is however a TCP traceroute (called 
tcptraceroute, funnily enough), which gets round this by tracing to a 
particular TCP port. Handy then as you can trace through firewalls to 
the final destination :)

tracert on Win32 however is ICMP based. Which can be worse than the UDP 
traceroute, especially in the current climate of worms.

Chris...

-- 
\ Chris Johnson           \ NP: Dream Disciples - 10. A Cure For Pain
 \ cej [at] nightwolf.org.uk    ~-----,   
  \ http://cej.nightwolf.org.uk/  ~-----------------------------------, 
   \ Redclaw chat - http://redclaw.org.uk - telnet redclaw.org.uk 2000 \____



___________________________________________________________________

Sheffield Linux User's Group -
http://www.sheflug.co.uk/mailfaq.html

  GNU the choice of a complete generation.