Re: ssh on ping port?

James J. Dines wrote: 
Snowbat wrote:

On Sun, 15 Jan 2006 17:01:54 -0600, Beowulf wrote:

Is there any reason why ssh and its daemon sshd could not be run on the
port normally used for ping?


Yes - ping doesn't use a port.

http://en.wikipedia.org/wiki/ICMP 

Ping absolutely *does* use a port.  Ping is a program which sends ICMP ECHO
REQUEST and receives ICMP ECHO REPLY.  On my Mandriva Linux 2006
box, /etc/services shows that port 7 is used.

type (in a terminal, of course):
cat /etc/services | grep echo
... to verify this.

tcp/udp port 7, the echo service, is NOT the same as an icmp echo request/reply used by the ping program. Please do not confuse an icmp (control) packet with a tcp and/or udp packet. The icmp protocol do NOT use the notation of ports, instead the icmp protocol is divided into different types where echo request is type 8 and echo reply is type 0.

For those who look into this on the wiki page, do not confuse port number
with ICMP message #.  The ICMP Type field for an echo request is 8, while
for echo reply, it is 0.  Both will use port 7 if that is
what /etc/services says to use.


Sorry, but this is not correct. Please see above.

.

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