HOW TO: Netcomm NB9WMAXX and Firewall

[Peter Garrett]

On Sat, 17 Jul 2010 00:07:00 +1000
Basil Chupin <blchupin at iinet.net.au> wrote:

> If a router doesn't respond to an ICMP ping then it does not exist. 
> Right? Or is this wrong?

From the headers of your mail:

> Received: from unknown (HELO [192.168.1.3]) ([124.171.111.123])
> 	by outbound.icp-qv1-irony-out6.iinet.net.au with
> 	ESMTP/TLS/DHE-RSA-AES256-SHA; 16 Jul 2010 22:06:55 +0800

So, your IP does indeed exist, regardless of pings, and indeed if
someone read the headers they would also know the LAN address of your
machine (192.168.1.3).

If I wanted to know more I could point nmap at your IP and scan to see
if anything was listening. (I won't, and neither I hope will other
list members).

The fact that you can or cannot be "pinged" is completely
irrelevant.

Also, it's worth remarking that disallowing icmp is actually against
the "RFC" rules (Requests For Comments). So, good Netizens don't block
pings ;)

grc.com deals in scare-mongering. The "Shields Up" facility is useful,
but the insistence on so-called "stealth" is nonsense. 

Peter
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