HA highly dependant on DNS, HA wont work without proper DNS configuration. ESX servers and vCenter server should be able to resolve name(FQDN)/IPs in both direction to get HA work
Your statement is not entirely true, HA is highly dependent on standardised naming, there is no requirement for DNS, DNS just makes it eaiser to setup as there is a single location. Correctly configured Host files work just as well. I have worked in locations where there is no DNS, and host file configuration works fine
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Tom Howarth VCP / vExpert
VMware Communities User Moderator
Blog: www.planetvm.net
Contributing author on "[VMware vSphere and Virtual Infrastructure Security: Securing ESX and the Virtual Environment|http://www.amazon.co.uk/VMware-VSphere-Virtual-Infrastructure-Security/dp/0137158009/ref=sr_1_1?ie=UTF8&s=books&qid=1256146240&sr=1-1]”. Currently available on roughcuts