interesting DNS issue

Question

One vm deployed to azure, has a connection to four endpoints that are local servers all joined to a domain. The Azure VMrole has a HOSTS file that gives it public addresses for certain resources. These resources also have internal IP addresses.

Out of the blue, the Azure VM will begin using the internal IP addresses, even though there are HOSTS file entries. It is not configured to use local DNS server, only pointed to the local domain controller so it can join the domain.

Question: how is it resolving to the local IP address instead of the public IP address for these resources? How is this possible? Shouldn't it use the Azure DNS server and the HOSTS file shouldn't even be necessary correct?

Answer 1

Hi,

Can you provide more details abput your application structure? It seems you want use HOSTS files for give a public address for all certain resources, and you do not want use VM Role internal IP address, right?

Thanks

Answer 2

How can Azure host, in a vmrole get an internal DNS address from a domain it's joined to if it is using the Azure DNS server as it's DNS server? If it was using the domain internal DNS server instead of Azure I could understand.

Also, how can an Azure host in a vmrole ignore a HOSTS file in system32\drivers\etc and use an address other than what is in there?

The resource in question has an external IP address and an internal one. The Azure vmrole host should be getting the external IP address and usually does, even without the HOSTS file. Every once in a while though, it will magically try to use the internal IP address for the resource and I'd like to understand how it is getting that IP address. The Azure DNS server should not have the internal IP address.