Without going down the path of a HALB as we don’t have huge numbers of users whats the best way to setup https://ras.mydomain.com to utilise our 2 gateways for HTML5 clients. ie: we just want users using a vanity type URL instead of picking a gateway URL.
is it just to setup an A DNS Record for RAS.mydomain.com with two A entries of the IP addresses of both gateways?
Having a single DNS record with two IP addresses will give you the vanity URL but no fallback in case of failure. The real show stopper will probably be that the html5 client/user portal is not stateless – the same server needs to be used throughout the user’s session. For the time being, I don’t think you can reliably use multiple html5 gateways without using a load balancer (e.g. HALB, but really, any load balancer with cookie session persistence “should” work).