Thursday, January 20, 2011

DNS trouble - think it might be caused by two NS records

Hi,

About a week ago, I updated my DNS, adding:

HOST, TYPE, VALUE, TTL
*.soup-team.com CNAME www.myopenid.com 3600
mail.soup-team.com CNAME ghs.google.com 3600

HOST, TYPE, VALUE, MX, TTL
soup-team.com MX aspmx.l.google.com 10 3600
soup-team.com MX alt1.aspmx.l.google.com 20 3600
soup-team.com MX alt2.aspmx.l.google.com 20 3600
soup-team.com MX aspmx2.googlemail.com 30 3600
soup-team.com MX aspmx3.googlemail.com 30 3600
soup-team.com MX aspmx4.googlemail.com 30 3600
soup-team.com MX aspmx5.googlemail.com 30 3600

From before, I had:

HOST, TYPE, VALUE, TTL
soup-team.com A 64.120.188.121 3600
soup-team.com NS ns01.000webhost.com 3600
soup-team.com NS ns02.000webhost.com 3600
www.soup-team.com CNAME soup-team.com 3600

Additional details:
The domain is purchased from www.proisp.no
www.everydns.com is used for DNS management.

Now, from home, everything works perfectly, but from the university, neither mail.soup-team.com nor any of the OpenID-related subdomains are working. Instead, an error-message from my webhost (000webhost), is displayed - err.000webhost.com.

I've used OpenDNS's CacheCheck (www.opendns.com/support/cache/) to check their cache as I thought this might help me identify the problem. After requesting a refresh (yesterday, and today), all of their caches point correctly to mail.soup-team.com and most of them to the OpenID-related subdomains (which caches are not updated seems to differ for different usernames).

I have a theory that the problems might be related to some caches ignoring the *.soup-team.com rule and instead querying the 000webhost Name Servers.

So, my questions are:
1) Have I made any sort of misconfiguration?
2) Since I have an A record pointing to the IP of 000webhost, and I'm not using their subdomain option, can I remove the NS records (ns01.000webhost.com and ns02.000webhost.com) without causing other kinds of trouble?

Thanks in advance,

method139

PS: I'm quite new to DNS. If I'm using the wrong words to describe something in this text, I'm more than happy for any feedback related to that as well.

  • My theory seems to be correct. From the mentioned CacheCheck, after having refreshed the cache, I followed a link named "Check a third-party tool", and here is what I got:

    DNS Traversal for method139.soup-team.com

    Note how the 000webhost Name Servers respond "[Broken DNS server: Reports that it refuses to respond!]". Yet the main website (soup-team.com) still work.

    This means that since I only host the main site at 000webhost, and I have a working A rule, I won't need the two mentioned rules.

    PS: I will soon change the OpenID from username.<domain> to username.id.<domain> (as I think username.<domain> should be used for other purposes than just OpenID), so if anyone attempts to check it for themselves at a (much) later point, the output that they get from the tool will be different. And, of course, if I am correct in my theory, the problem will soon be resolved, so you won't see the same anyhow.

    From method139
  • caches ignoring the *.soup-team.com rule

    That would be a very big brokeness. It is quite unlikely, wildcards exist in the DNS from the beginning.

    From bortzmeyer

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