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Re: Port Knocking questions
From: Ansgar -59cobalt- Wiechers <bugtraq () planetcobalt net>
Date: Tue, 2 Mar 2004 02:03:35 +0100

On 2004-03-01 H Carvey wrote:
Does it require the hacker to be able to ping the device?

Again, it depends on the implementation.  If the author of the
application using port knocking requires an ICMP packet to be in the
mix, then the answer would be "yes".

Not necessarily. I suppose we can assume that "being able to ping" means
that the remote host will respond with icmp-echo-replies to icmp-echo-
requests. For ICMP-based port-knocking (does this make sense at all,
since ICMP does not have ports?) the host will only need to log incoming
ICMP packets, but won't have to send echo-replies. Thus the caller won't
be able to ping the device.

Ansgar Wiechers

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