Hi ,
I do have an Exchange Server 2010 SP1 running in my environment. I do have 3 Mailbox server on single DAG, few day back I found my machine was getting fail-over without any issues on server. Viewing the log I found that there was an event of Event ID 1177 and 1135. It suggested to validate the Clustering of the servers and while checking the server cluster. I found the validation getting freeze on Network Validation.
Even I tried to check the Network Stability by transferring 6 GB of single file from one Mailbox server to another, it got failed. Below is the snap of my Cluster Validation. Request for your help on this.