Wednesday, 16 September 2009

HA deployment of IAG, using CLB

I spent the last couple of days in Wakefield, helping out a reseller with a high available deployment of Celestix WSA appliances using Celestix Load Balancers. Thanks for the company David!! :)

We started by configuring the Celestix Load Balancer (also known as CLB), after configuring the solution we were informed that the internet lines would be a number of weeks away, and we would not know whether the IPs that would be provided would be either external internet facing IP addresses, or NAT'd internal addresses. Why would this be an issue?

Well the customer wanted four IAG portals to be created, and as each portal would have to be created on both appliances. With the CLB in front of the IAG appliances, the way the IP addresses are presented will impact on how to deploy the solution.

If the addresses are external facing, we would need 12 external IP address, three for each portal (one on each appliance, and one for the virtual IP). If the addresses are NAT'd, then there would only be a need for one external address as the virtual IP on each portal.

We only configured one IAG appliance, and then backed up and restored the configuration on the second IAG appliance. Obviously the IP addressing needs to be changed, and the certificate information to be modified, but that was pretty much it.

We were deploying OWA, Sharepoint, Citrix, Mapped Drives, File Access, RDP and an IIS based intranet site.

From an authentication perspective, we looked at AD, AD & HOTPin, AD & Vasco Middleware (RADIUS) and just HOTPin. As expected the authentication methods were straight forward and I got a chance to use HOTPin a bit more. We configured HOTPin on the primary box, and had the secondary box referencing the primary box. You only have to allow port 10000 access between the appliances, and using local administration credentials is fine. The only pain was HOTPin not scanning AD correctly in subtrees, which means each OU would need to be defined when importing users, but I'll let Celestix know about that.

We also encoutered the Java issue, so that was resolved using the fix from one of my previous blog posts.

We can only complete the deployment, once we know how the IPs will be presented.... which will also impact the way we can balance the load (do we use DSR or not, VRRP, Loopback adapter configuration, etc, etc).... Let's see!