Two AD domains with a wildfire

Environment: FC4 - Wildfire 2.6.1 + PyMSNt. authentication LDAP with AD domain working. AD Server 2003 with subdomain (subdomain.domain). Pandion and Spark clients

It’'s possible auth subdomain users and domain users with only a Wildfire Server?

How !!

Do you have multiple forests in AD?

No, I have one forest with a main domain and a child domain.

And I’‘d like authenticate both domain’'s users with a wildfire server.