Dns

certm0de

My work website has the same name as our domain. The website is hosted by an external company. When users try to access the website internally, the webpages will not load all the images. I'd say only 60% of the images load. I've created an A record in the forward lookup zone named www and the IP address, I've also created a reverse lookup zone. When I use an alternative dns server such as google, the web page loads as it should. What gives? I've flushed/registered the DNS cache on both the client and server to no avail. Any ideas?

Dojiscalper

That is a very interesting problem. Wish I had the answer, I don't understand how some images work while others don't. Once your pointed to the web address via dns I would think the web site code takes over and you get everything.

My thought, the images that load, do they happen to be local to the websites index file? Then are the images that aren't loading being linked from anywhere else that perhaps needs a pointer created?

poolmanjim

So the images now showing is likely a result of the way they are configured to display on the webpage. Images are displayed one of two ways, normally, on websites: absolute path or relative path.

Absolute Path is the image is specifically pointed to a location on the website (e.g. http://www.example.com/images/image.png)

Relative Path is when the website fills in some of the gaps based on some of the header information and the url the client put in. (e.g. ..\images\image.png).

I'm guessing some of the images use relative path while others use absolute path.


Now to move on to your DNS issue as a whole. Split brain DNS is incredibly difficult to manage. It takes careful management to make sure that its all redirected correctly. You could try to have your traffic going to the website routed differently, which may help. The best option would be to reconfigure your internal network to use a different domain. Right now the domain and the website are using example.com as the root. For your website, leave it as example.com but change your internal domain to be something like corp.example.com. If you configure it right, it isn't a child domain and is, in fact, a full forest separate from your website just using the same "namespace".

rsutton

poolmanjim nailed it and I agree that you likely have images using relative paths in the website code. I've seen a lot of companies use split brain DNS due to how AD was seup, e.g. using domain.com instead of domain.local. If your AD DNS name is the same as your public domain, you would have to either a) rename the AD FQDN or b) re-code your website to use absolute paths. If your AD name using the public FQDN, then you should investigate the ramifications of removing that public zone from internal DNS.

certm0de

Poolman you're correct we are using split brain dns. The website was working fine the day I don't know what happened. Another thing I observed by viewing the website source code is some links are pointed to static.mydomain.com as the address. I've created a CNAME record named static and it still does not work. Any ideas?

certm0de

I fixed the issue by restoring one of my dns backups with the dnscmd. Remember to backup folks.