Re: Port function and scanning

Sebastian G. <seppi@xxxxxxxxx> wrote:
Volker Birk wrote:
number). Port scanners are more seldomly used for UDP, because there is
no algorithm for this case for UDP.
There is.
no reply -> open or filtered
Wrong. No reply: open or closed.
The Nmap documenation and the real world systems' behaviour tell something

That may be your view.

From RC 792:
| The Internet Protocol is not designed to be absolutely reliable. The
| purpose of these control messages is to provide feedback about
| problems in the communication environment, not to make IP reliable.
| There are still no guarantees that a datagram will be delivered or a
| control message will be returned.
Is that your argument of a misguided quote?

I fear, you just don't understand.

ICMP has message codes and subcodes, which are essentially similar to ports.
No, they aren't. ICMP is a messaging protocol using IP packets, and the
message codes have nothing to do with a port concept.
They aren't used directly for multiplexing, however this is done by
providing a part of the initial IP packet - which tells the host to which
packet the reply belongs.

Strange view.

I cannot see any argument in your posting which persists.

"Es muss darauf geachtet werden, dass das Grundgesetz nicht mit Methoden
geschützt wird, die seinem Ziel und seinem Geist zuwider sind."

Gustav Heinemann, "Freimütige Kritik und demokratischer Rechtsstaat"