New website DNS nightmare!

[Deanuk]

Afternoon all,

 

I come to you edu gurus as a last resort, the issue I'm about to describe has been doing my nut in for a few hours now! Yesterday we launched a new school website, all is working fine off site. However, when trying to access the website from an school computer they receive a page cannot be displayed error.

 

After a bit of good old fault diagnosis I have manage to track the issue down to a DNS error. From my desktop NSlookup shows "Non-existent domain" I checked the DNS manager on server 2016 domain controller and found a forward lookup zone HOST A record for the website, this fed to an IP which was obviously not used anymore. I removed this and still no luck, I changed the DNS server manually on my desktop to open DNS as a test and got instant access. However, when changing back to my DC I struggle to any connection.

 

I have all so added a www CNAM record for FQDN but this has not worked either!

 

Any ideas?

 

Thanks in advance.

Edited May 1, 2018 by ZeroHour

[mrwoberts]

Now you've corrected the internal DNS zone records, could it be just a matter of refreshing the clients DNS cache.

 

ipconfig /flushdns
ipconfig /registerdns

 

If you use Chrome, you may also have to flush out its own DNS cache...

 

type this in the address bar

chrome://net-internals/#dns

 

Then click clear host cache.

[psydii]

Rather than removing the incorrect record on your internal DNS server you need to update them with the correct information.

 

 

(It seems likely that your internal network uses the same domain name as your website, so you have implemented 'split-brain' DNS. Your public records have been correctly updated but your external ones still need work)

[Chris_Jones]

I assume you have a local copy of your DNS Zone?

 

so if the website is http://www.myschool.sch.uk you need to create a local A record for www in the myschool.sch.uk zone, deleting the old one just causes an entry not found error

[Deanuk]

Hi Guys,

 

I have contacted the new web hosts and they have managed to provide me with an IP so I can create a new A record within the DNS manager. I have created this but I seem to be having an issue with an extra www. being placed in fron of the domain, I think that this is a propagate issue so I will wait a few hours before investigating further.