Eliminate Logon Delays When DNS Connectivity Is Poor
If connectivity to your DNS servers is tenuous or becomes unavailable, name resolution can time out, delaying the logon process. Because Active Directory is heavily dependent on a well-functioning DNS system, you should work to resolve your DNS issues.
If you cannot fix your DNS system, however, you can as a last resort set up a caching-forwarding name server on the AD Bridge Enterprise client to eliminate the logon delay. For instance, you can set up a BIND server on each Linux or Unix computer on which you are running AD Bridge Enterprise. Then you can configure BIND as a local caching resolver and add your nameserver addresses to the forwarder list, leaving /etc/resolv.conf with only the local loopback address:
search example.com nameserver 127.0.0.1
For instructions on how to set up BIND, see the BIND documentation.