WinAD manual authentication to two domains

Hi,

We have our windows 2008 domain (A) and a secure windows domain (B) which we have a one way forest trust with.  Their trust of us is listed as 'External, not transitive'.

So

A - Forest, Transitive -> B

B - External, Not Trans -> A

We are running web sphere on windows 2008 R2, BOXI 3.1 SP 5.

We have set up WinAD manual authentication with our domain A using Kerberos.  Reading the documentation and threads here, it's obvious we cannot add domain B without creating a forest trust from the other side.  This will not happen for security and policy reasons.

Should we be able to configure BOXI manual LDAP authentication to their AD and have it coexist with the WinAD auth?

Thanks,

Sam