Check to make sure DNS is configured properly
Check to see if you can resolve DNS
Check DNS records
Make sure you are using FQDN’s
Check your /etc/hosts file
Make sure your using lower case
Check Service Consoles have the same names and networks
Disable and Re-enable HA
Select Reconfigure for HA on the ESX host
Out of these troubleshooting tips the most common problem with HA is a DNS issue, so it is best to start troubleshooting DNS first.
I got this from here,
Thanks for the info..it helped me.