Resolve LDAP authentication issue in a differentes domain AD with trust relationship

[Deleted user]

Hi, we are installing Jira in a DMZ network and we have to authenticate with an external AD (wich has trusted relationship with our internal AD). 

Our environment has: 

- Internal network with internal AD

- a DMZ network with external AD with trust relationship  (external trust in Internal but internal doesn´t trust in external).

we can't grant applications in DMZ authenticate in Internal AD (filtered via firewall)

How can we set and  authenticate our internal users in DMZ with external AD ?

Regarding our understanding we can´t set doman & user in Jira Login, 

How can we set different domain when we are login in?