We have about 5 dns servers. For the last month, rougly once a week dns services will just stop on one of the servers. When we check the logs we see lots of 4010 and 3000 errors in event viewer. This happens on one server one week and then a different server the next week. We start dns services backup and everything is fine. The only suggestion i saw on EE here is to allow zone transfers. We have our servers set to not allow zone transfers. So first i'm wondering why we would have it set that way and secondly what is causing those errors. Thanks in advance for your help.