IBM HTTP Server version for Reverse Proxy
Accepted answer
You can find the System requirements on the Getting Started Tab for each download.
Here is it for 6.0.2 https://jazz.net/wiki/bin/view/Deployment/CLMSystemRequirements602 . For WAS there is support listed for 8.0 (8.0.0.6), 8.5 (8.5.0.2), 8.5.5 and future fix packs. IHS usually is part of the WAS downloads and so I would assume you should use a compatible version.
Here is it for 6.0.2 https://jazz.net/wiki/bin/view/Deployment/CLMSystemRequirements602 . For WAS there is support listed for 8.0 (8.0.0.6), 8.5 (8.5.0.2), 8.5.5 and future fix packs. IHS usually is part of the WAS downloads and so I would assume you should use a compatible version.