[olug] VNC w/Qwest

[Kenny Kant]

Very interesting thread, but I am curious about DHCP and its use of
ICMP/Pinging.  I have never heard of this being used when describing the
function of DHCP, could you explain further?  What component of the dhcp
model performs the pings?  I have always thought this was the role of
the database maintained by the dhcp server itself.  If your statement
were correct I think we would have many networks fooked as I have seen
many DHCP enabled networks in conjunction with about 3/4 of the hosts on
that segment running Windows Software Firewalls all of which are denying
receipt of ICMP echo requests.

Kenny


On Mon, 2007-10-15 at 15:42 -0500, Luke -Jr wrote:
> On Monday 15 October 2007, Obi-Wan wrote:
> > >> I'm not even able to ping his IP.
> > >
> > > Then quite frankly, a network is misconfigured.
> > > You should always be able to ping a used IP address.
> >
> > Alas, that's not true.  Pings are just another type of network packet,
> > and are quite commonly blocked by firewalls.  I often run into situations
> > where a company allows HTTP in, but not ICMP.  Makes debugging a PITA.
> 
> ICMP is a network infrastructure protocol. Networking standards assume it is 
> always in place. For example, DHCP uses pings to determine if an address is 
> in use. IP autoconfiguration generally will not work at all without ICMP.
> Even if you do not need these standards, disabling ICMP is still broken.
> 
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