Re: UDP port 22

From: Jacob Nevins (jacobn_at_chiark.greenend.org.uk)
Date: 04/28/04


Date: 28 Apr 2004 12:55:51 +0100 (BST)

Mike Mimic <ppagee@yahoo.com> writes:
>I found out that on my system (Debian) there is in /etc/services
>written that UDP port 22 is used by SSH. How is that? Is not
>ssh only TCP? Is this a mistake?

How strange. True of my system too, and of the IANA's registry:
<http://www.iana.org/assignments/port-numbers>

They also provide similar UDP assignments for a number of other
well-known protocols such as ftp, telnet, and smtp, none of which have
UDP components as far as I'm aware.

Perhaps they just do it to avoid those ports being assigned to anything
else, to avoid confusion. "To the extent possible, these same [TCP] port
assignments are used with the UDP [...]".



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