Help needed...any DNS gurus out there?

[jon h]

Our ISP at work have comprehensively c0cked up an apparently simple change I asked to be made to our domian records.

They say it is our problem, I am convinced it is not... The bottom line is that after 3 weeks, they have still not resolved the issue, and a large chunk of our e-mail is going missing. I think it is because there is a CNAME set up incorrectly, but then I am no expert (nor, it seems, are they!)

They have created a CNAME record for our domain as "domain.com" (NOT www.domain.com)then the real server name where they host our web site. This is, I guess meant to point web traffic in the right direction, but somehow, som of our e-mail is being routed to the server where our web site is hosted and not our mail server, as if some mail servers are trying to resolve our domain via the cname record. (There is a correctly configured MX record for our domain)

Any thoughts? I personally think that the CNAME record should be for "www.domain.com", but then I have been on a crash course out of necessity and an no DNS guru...

Thanks in advance

Jon H

[randlemarcus]

When I do a ls -d domain.name:

domain.name. SOA ns1.powerhost.co.uk dnsadmin.eechost.net.
(2006071701 10000 1800 604800 21600)
domain.name. NS ns1.powerhost.co.uk
domain.name. NS ns2.powerhost.co.uk
domain.name. A 217.69.41.103
mail A 217.69.40.72
www A 217.69.41.103
ftp CNAME www.domain.name
pop A 217.69.40.73
smtp A 217.69.40.69
mailadmin A 217.69.32.28
webmail A 217.69.32.28
dcp A 217.69.47.68
domain.name. MX 1 mail.domain.name
domain.name. MX 10 mail.domain.name
domain.name. SOA ns1.powerhost.co.uk dnsadmin.eechost.net.
(2006071701 10000 1800 604800 21600)

So yes, CNAME is set to www.domain.name, but should affect mail and the MX records flow that through. Tell us the name, and we can see if the DNS records throw any nmore light on things...

Marcus

[JamieBeeston]

MX Records should NOT point to a CNAME, the should point to an A Record.

Whilst CNAMES have their uses, I find it far easier to just have the following

A Domain.com
A www.domain.com
A mail.domain.com
MX for domain.com to mail.domain.com

Bobs' your uncle.

If you need to, drop me a mail and I'll give you further analysis of the domain in question.

This is a 5 min, not a 5 week fix.

J

[randlemarcus]

Spot the missing NOT between should and affect.

Not edited so as to appear even less literate than I am

[_dobbo_]

Part of your problem may be that even using Jamie's advice above (which is absolutely correct for mail routing) some older mail servers don't understand MX records (I'm talking really old) and other mailservers will fail over to an A record for a domain in the event that it takes too long to resolve an MX record.

Most people point an A record at the WWW server, which very often is running it's own SMTP service for one reason or another. What may be happening is that even with a correct MX record in place, servers are still connecting to your A Record which is bouncing the mails.

To resolve this, your WWW server needs to be configured to either not run it's own SMTP service, or to route mail onto the primary MX record, in what is effectively a backup MX capacity.

[JamieBeeston]

Ben,

I think the issue is simply his ISP have fudged the DNS totally, initially an A record was deleted, then it was replaced with an incorrect IP iirc, once someone competent gets their hands on the DNS it should be resolved same day.

J