Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I questioned the decision of a colleague concerning the use of a HOSTS file entry on an application server (standard SQL database backed .NET solution), which I think would cause connections to the SQL Cluster to connect only a single node in the SQL Cluster. In other words, the by using a HOSTS file entry like this....        SQLCLUSTER

...when the IP address above is the IP address of the active node in the SQL cluster and the application connection string contains SQLCLUSTER as the data source.

Intuitively, I would think the clustering technology would fail in an Active-Passive cluster configuration when using HOSTS files as described above. I do not have in-depth knowledge of MS SQL clustering, just more traditional network load balancing. Am I correct?

share|improve this question
up vote 2 down vote accepted

Hosts file?!! I'm going to keep this short and sweet... you should be using AD DNS.

Clustering uses many facilties and one of the main requirements is an AD and DNS infrastructure. It uses this for many of its configurations and features. While in theory a hosts file might work with some hackery it's not best practice nor a supported configuration.

share|improve this answer
I know, I'm very concerned about the heavy use of HOSTS files on this project. – codewise May 2 '12 at 17:26

It won't work. The SQL service will be listening on the cluster IP address, not the individual server's IP (unless you configure things to behave otherwise).

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.