[SunHELP] ping a port

[Adam Kropelin]

Yes, that's basically what I meant by "The network stack is what responds to
a PING (really an ICMP echo request packet), not any particular
application".

I think there is unlikely to be anything dedicated to the job of listening
for and responding to pings, i.e., a "ping server". Stevens is the expert,
for sure, but I expect it's just a terminology issue. I'm fairly certain
that there is basically one piece of kernel code that looks at what sort of
ICMP packet has arrived and deals with it appropriately. A redirect, for
instance, would result in a temporary change to the routing table, while an
echo request begets an echo reply. I would be very surprised if there is a
kernel thread dedicated to being a "ping server". If there is, I'd like to
understand why.

--Adam

----- Original Message -----
From: "Kovalev, Ivan" <Ivan.Kovalev at tfn.com>
To: "'Thomas Cameron '" <archimage at linux-magic.com>; <sunhelp at sunhelp.org>
Sent: Saturday, September 22, 2001 12:09 PM
Subject: RE: [SunHELP] ping a port


> A little correction to Adam's reply: "...ping server is normally part of
the
> kernel's ICMP implementation" (Stevens)
>
> -----Original Message-----
> From: Thomas Cameron
> To: sunhelp at sunhelp.org
> Sent: 9/22/01 12:54 AM
> Subject: Re: [SunHELP] ping a port
>
> Thanks for the clarification.  I wasn't sure what exactly to call the
> ICMP connection other than "port," but I thought that wasn't quite
> right.
>
> TC
>
> Adam Kropelin wrote:
>
> > AFAIK, there is no such thing as a port in ICMP. ICMP packets are
> > demultiplexed by IP based on the value of the protocol field in the IP
>
> > header. The network stack is what responds to a PING (really an ICMP
> > echo request packet), not any particular application.
> >
> > --Adam