What is the sense of telnet on 53 port?

[Brad Knowles]

At 11:25 AM -0700 7/26/01, Kankossa wrote:

>  I'm installating a DNS server. Can I use telnet on port 53 from any
>  machine is considered as a test of DNS?

	Nope.

>                                           Or it has no sense since DNS
>  is UDP protocole while telnet is a TCP protocole?

	No, DNS packets can be transmitted over either TCP or UDP. 
However, it is not a plaintext format, but a binary format. 
Therefore, you cannot use a telnet plaintext application to 
communicate directly on port 53.  Instead, you need to use DNS query 
and debugging utilities, like dig, doc, dnswalk, etc....

>                                                     Then if I connected
>  to to the server, what this means?

	It accepted a TCP connection, but then didn't know what to do 
with a client that spoke a different protocol.

>  More preciously my troubles are:
>  - Is "telnet IP_AD 53" where IP_AD is the IP addresse of my DNS
>  machine means that my DNS Works?

	Nope.

>  - Is "telnet FQDN 53" where FQDN my be any domaine on the net prove
>  that my DNS works fine?

	Nope.

>  PS: I know that nslookup exist and my be more appropriated, but I want
>  to know about the above questions.

	IMO, nslookup is evil.  It should be avoided unless you have 
specific reason to know you want to use it.  Use dig instead.

-- 
Brad Knowles, <brad.knowles at skynet.be>

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