APM Active Directory Trusted Domains - how to use?

Hello,

I'm facing a similar problem

As I understand you have to set up first a trust relationship between DomainA and DomainB and then you configure the AD Trusted Domains in the APM.

https://support.f5.com/kb/en-us/products/big-ip_apm/manuals/product/apm-authentication-single-sign-on-11-5-0/2.html

The one that is configured as root is going to be asked for a Ticket to authenticate against the other domains.

https://blogs.technet.microsoft.com/mir/2011/06/12/accessing-resources-across-forest-and-achieve-single-sign-on-part1/

So the root AD should be DomainA AD for A Users or DomainB for B Users.

Also another option could be Split the users by domain and authenticate each one with their AD, something like this:

https://f5guru.com/2014/11/17/apm-cookbook-multiple-domain-authentication-part-2/

Good luck!