subdomain works for some, not for others

[JohnnyBob]

Using cPanel...

I have a subdomain setup as "forum.mydomain.com" to redirect to my phpBB forum at:
http://www.mydomain.com/phpBB2/index.php

The link http://forum.mydomain.com works OK for me and most forum members, but some of my forum members report that it won't work for them. Only the direct link http://www.mydomain.com/phpBB2/index.php works for them.

What could cause this kind of problem?
Is there any way to make the sub-domain work for everyone?

 

[krava]

Check httpd.conf and make sure ServerAliases exists for:
forum.mydomain.com
and
www.forum.mydomain.com

Additionally, check the DNS zone entries of mydomain.com. There must be A or CNAME records for the subdomains. Actually, dig the nameservers of your domain name and check if both nameservers answer correctly. The dig command looks like:

#dig @ns1.nameserver.com forum.mydomain.com

#dig @ns2.nameserver.com forum.mydomain.com

I believe there is some problem with the DNS zone entries.

 

[JohnnyBob]

Check httpd.conf and make sure ServerAliases exists for:
forum.mydomain.com
and
www.forum.mydomain.com

Additionally, check the DNS zone entries of mydomain.com. There must be A or CNAME records for the subdomains. Actually, dig the nameservers of your domain name and check if both nameservers answer correctly. The dig command looks like:

#dig @ns1.nameserver.com forum.mydomain.com

#dig @ns2.nameserver.com forum.mydomain.com

I believe there is some problem with the DNS zone entries.

Thanks, but I don't know how to do any of those things. I would need specific detailed instructions.

 

[krava]

JohnnyBob, can you detail what subdomain exactly doesn't work ? I will run the test myself and let you know what you need to do exactly if my guess is correct.

 

[JohnnyBob]

Thanks very much...

forum.johnnybob.com

redirects to

http://www.johnnybob.com/phpBB2/index.php

Is that the information you need?

 

[krava]

Ok, seems I know what exactly is causing the problem and as I said the problem is related with the DNS zone entries of your domain. Actually, the subdomain isn't working for some visitors because the DNS zone of your domain contains incorrect DNS servers:
http://dnsreport.com/tools/dnsreport.ch?domain=johnnybob.com
According to the DNS report provided above you domain name uses the nameservers:
ns5.ardenthosting.com
ns6.ardenthosting.com
but the DNS zone conatins entries for the nameservers:
dns43.gzo.com
dns44.gzo.com
If you has root access to your server, then log in to WHM as root, click on "Edit DNS Zone", find your domain name, select it and click on "Edit".

Find the records:
johnnybob.com. 86400 IN NS dns43.gzo.com.
johnnybob.com. 86400 IN NS dns44.gzo.com.
and repace them with:
johnnybob.com. 86400 IN NS ns6.ardenthosting.com.
johnnybob.com. 86400 IN NS ns6.ardenthosting.com.

save the edited DNS zone, wait a few minutes and your subdomain will work for everyone.

If you can't log in to your server as root, then I advise you to contact your hosting provider and ask to resolve the issue with your DNS.

Hope it helps you.

 

[JohnnyBob]

Thanks very much.
I'll provide this information to my host provider.
Hopefully they can fix it.

 

[krava]

It isn't hard to resolve the problem and I think your hosting provider will update the DNS zone soon.

Have a good day

 

[Infopro]

You might want to wait to make sure it has resolved before making additional changes.

 

[JohnnyBob]

I found a different solution, apparently, at least the Status column in my johnnybob.com's DNS Report no longer has any fail/red areas.

I have good customer service from my domain host. He advised me that the way to fix it might be to switch from their "alias" ArdentHosting nameservers to the "real" GZO nameservers. So that's what I did and it got all the red out.

An independent testing report from a tech-friend says it fixed it for him, at least. I'll have to wait a few days/weeks before I can swell up with megalomaniacal pride, but I feel optimistic at this point. :p

 

[krava]

Yes, it is possible to resolve the issue this way too. However, in this case you will have to wait 2-3 days while the DNS zone of your domain name is propagating. Additionally, you will have to edit your DNS zone everytime when you add a new subdomain or an addon domain.

 

[JohnnyBob]

Thanks again!
I'll avoid creating any new subdomains, for awhile at least...

 

[JohnnyBob]

More questions come to mind, after the fact, so to speak...

DNS Reports says a large percentage of domains have a DNS problem. After testing a few, I can see that most of them have at least one red failure warning in the Status column. So that seems to be true, but is that really reliable information? In other words, is DNS Reports being "too picky" about minor faults?

What is the root cause of this problem? If it's so widespread there must be some serious bugs out there. Where are those bugs?

Is it a deficiency of my host? In other words if I transfer my website, subdomains, etc to a different host, will that fix it? If so, is there a list of hosts that have/don't have this problem? That would be valuable info to have before going to the trouble of switching hosts but I don't see it mentioned anywhere.

You say that I need access to my DNS zone, or some such, to fix it myself. But I've had 3 hosts in the past and none of them provided that access (insofar as I'm aware). Are there hosts that provide it? If so, who are they? Or how do I go about getting access to my DNS zone?

Is it a bug in cPanel? If so when will it be fixed? Or is there an add-on that will fix it?

Is it a bug in the server software? Or could it be a faulty server?

Does it only happen when creating subdomains? In other words, if I avoid creating/using subdomains will that avoid this DNS problem?

 

[krava]

Sorry, but I need to know the exact domain name to check it and investigate what causes the problem. Anyway, DNSREPORT is really cool thing and it allows to determinate different DNS problems. According to my investigations RED warnings must be fixed, because even if the problems aren't visitble they cause big problems.

Yes, usually hosting providers don't allow to mange the DNS zones. So you need to contact your hosting provider and ask to fix the problem. If they are familiar with that, then they will resolve the problem soon. If not, then perhaps your hosting provider isn't very good.

Anyway,the problem isn't caused by cPanel. The server where your accounts are located is configured incorrectly.

 

[JohnnyBob]

...Anyway,the problem isn't caused by cPanel. The server where your accounts are located is configured incorrectly.

Aha! So it is related to the host, because different hosts use different servers. That suggests a possible solution. Run the DNS Reports for some sample domains from a prospective host you're considering. Then only signup if the DNS Reports are clean (no red warnings in the Status column). Would you agree that this is a good method to avoid DNS problems?

 

[krava]

Yes, that's good, but in any case I advise you to check your domain names using DNSREPORT when the domains are installed and pointed to the new server, because the DNSREPORT could show errors for some domains and not for others.

So the only way to be sure the DSN zone is correct is to check the DNS zones of your domains.