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Re: MiNTNET

In <m0t3FGD-00014oC@SDF.LONESTAR.ORG>, Evan Langlois <ekl@SDF.LONESTAR.ORG> wrote:

> Alright, I tried doing a telnet to the DNS (using both domain an 53 - it
> seems to be the same port, right?).

Look in /etc/services: the `domain' service is (should be) assigned
port 53. The older `nameservice' service, which is no longer used
anywhere, is assigned UDP port 42.

> I connect OK, but ... what is supposed to happen?  No matter what I
> type, I get nothing back - is this the way its supposed to work?

IIRC the DNS client and server communicate through socalled resource
records, which are in binary format (the length of the data field is
variable, the other fields, like type and class, have a fixed length).

After establishing the connection, the client is supposed to send a
query (type/class/name in a resource record). The server responds with
a (possibly empty) set of resource records or an error indication.
This should be explained somewhere in RFC 1034/1035/1123.

> While I did it I checked netstat, and it showed my connection just fine,
> but it showed it on the TCP side, where a normal DNS lookup happens
> at the UDP side (normally from NCFTP).

The DNS may use either UDP or TCP. Queries should first be sent via UDP.
If the response comes back truncated, the query should be retried via
TCP. Zone transfer queries should always use TCP (reliability required).

> Any ideas why I can't get a name resolved?

Too many. :-) Have you tried with nslookup? What does it say?


Waldi