SSH authentication across multiple AD forests

[GWalker107]

Is it possible to authenticate SSH users in multiple AD forests using trusts?

For instance, I have the following configuration:

• FOREST A
  - Domain1
  - Domain2
  
  FOREST B
  - Domain3

I'd like users from all three domains to be able to log in to CentOS via SSH.

So far I've been able to join the OS to Domain1 and see users in both Domain1 and 2.

Any suggestions?

Thanks

-GWalker107