[Samba] Winbind restrictions with AD communication

[Jevos, Peter]

Hi all

I have two freeradius servers with ntlm_auth and local auth
The point is that sometimes  ntlm_auth stops to work on the primary server. When I test it from the command line with command /usr/bin/ntlm_auth.... ,  it says "No logon servers"

I noticed in the logs that there were 10 attempts per minute with wrong password from one of our routers. When I applied ACL on the router to block this attempts, ntlm_auth started to work
During this time standby radius with its ntlm_auth was able to communicate with AD

So the question is if there are some restrictions in samba ( winbind )  when it will stop to communicate with AD in some special cases ?
It happened few times with the same scenario

I'm using samba3x-3.5.4-0.70.el5

Thanks

pet