[Gllug] Problem with looking up MX record

[Alain Williams]

On Fri, May 09, 2003 at 01:31:34PM +0100, t.clarke wrote:
> -------------------------------------------
> Message from:-
> Tim Clarke  (tim at seacon.co.uk)
> Seacon Group Ltd / Seacon Terminals Ltd,
> Tower Wharf, Northfleet, Kent, DA11 9BD, UK
> Telephone: +44 (0)1474 320000
>       Fax: +44 (0)1474 329946
> -------------------------------------------
> 
> Hi
> 
> I wonder if someone with more knowledge of DNS than me can enlighten me !
> 
> After about a week I received a bounce on the domain name 'justinfarr.co.uk'
> - error message 4.1.2  to the effect that the domain could not be found.
> 
> Nslookup also 'hung' for a while and then returned nothing.
> 
> After trying 'set type=ANY' on nslookup I managed to get the name of a
> nameserver, which upon setting server='nameserver' in nslookup and doing
> another lookup, returned the required info.
> 
> I note that an email to a genuinely non-existent domain returns an error 5.1.2
> rather than 4.1.2,  so I am wondering if there is some kind of problem with
> my implementation of bind talking to the distant nameserver.
> 
> Any suggestions welcome, as it is rather annoying to find out after a week
> that mail could not be delivered to a valid address due to some sort of
> nameserver glitch !

Try what you did:
	[addw at mint addw]$ host justinfarr.co.uk
	;; connection timed out; no servers could be reached

Try what your MTA will do (look for Mail eXchanger records):
	[addw at mint addw]$ host -t mx justinfarr.co.uk
	justinfarr.co.uk mail is handled by 10 mail.netdirect-online.co.uk.
	justinfarr.co.uk mail is handled by 20 smtp-relay.netdirect-online.co.uk.

and both of those resolve to something.
I can connect to both, try:
	telnet mail.netdirect-online.co.uk. smtp

Try everything that I am allowed to see:

	[addw at mint addw]$ host -a justinfarr.co.uk
	Trying "justinfarr.co.uk"
	;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 52236
	;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 2, ADDITIONAL: 3
	
	;; QUESTION SECTION:
	;justinfarr.co.uk.		IN	ANY
	
	;; ANSWER SECTION:
	justinfarr.co.uk.	86380	IN	NS	ns1.netdirect-online.co.uk.
	justinfarr.co.uk.	86380	IN	NS	ns2.netdirect-online.co.uk.
	justinfarr.co.uk.	86380	IN	MX	20 smtp-relay.netdirect-online.co.uk.
	justinfarr.co.uk.	86380	IN	MX	10 mail.netdirect-online.co.uk.
	
	;; AUTHORITY SECTION:
	justinfarr.co.uk.	86380	IN	NS	ns2.netdirect-online.co.uk.
	justinfarr.co.uk.	86380	IN	NS	ns1.netdirect-online.co.uk.
	
	;; ADDITIONAL SECTION:
	ns1.netdirect-online.co.uk. 4980 IN	A	195.7.234.11
	ns2.netdirect-online.co.uk. 4980 IN	A	195.7.234.10
	mail.netdirect-online.co.uk. 4980 IN	A	195.7.234.4
	
	Received 211 bytes from 192.168.145.12#53 in 25 ms

It is possible that they were down for some time.

-- 
Alain Williams

#include <std_disclaimer.h>

FATHERS-4-JUSTICE - Campaigning for equal rights for parents and the
best interests of our children. See http://www.fathers-4-justice.org


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