The following error is reported when attempting to access a server in another Domain / Forest.
[root@linux1 ~]# /opt/quest/bin/vastool -u firstname.lastname@example.org search -U DC://@example.com
Password for administrator@EXAMPLE.COM:
ERROR: Could not authenticate as email@example.com
VAS_ERR_DNS: DNS record lookup failed
Unable to discover ANY domain controllers.
KRB5_KDC_UNREACH (-1765328228): Cannot contact any KDC for requested realm
Reason: unable to reach any KDC in realm EXAMPLE.COM
In the example above the server (linux1) that ran the vastool search command resides in MYDOMAIN.COM and the command is being run against the target domain EXAMPLE.COM.
The error is occurrs because MYDOMAIN.COM is not aware of the existence of EXAMPLE.COM
Create a DNS conditional forwarder in MYDOMAIN.COM for EXAMPLE.COM