[plug] no ping

[James Devenish]

Hi,

In message <40B030C7.9020405 at omninet.net.au>
on Sun, May 23, 2004 at 01:04:07PM +0800, Mark Saxon wrote:
> Cameron Patrick wrote:
> >I thought the reference was to bom.gov.au blocking ICMP, not the ISP?
[...]
> traceroute did not work for me either at least the host was unreachable.
> Which means that www.bom.gov.au  does have ICMP blocked.  As does my 
> provider.

As I understood it, the original reference was someone from Mark's
service provider saying that ICMP was "turned off" on their dialins.
This is clearly false, or Mark would not have been able to get
traceroute to work at all. BOM is also not "blocking ICMP" -- the !H
does in deed mean "host unreachable" and the "host unreachable" message
is itself carried back to you by...ICMP. What is much more likely on
both ends is that they are filtering out specific ICMP messages such as
ICMP echo requests or ICMP echo responses (but not ICMP generally --
that would be bad).