Turn off Multicast Name Resolution (LLMNR) to speed up Dentrix Treatment Planner

The Dentrix G6 installation went relatively smoothly for the Belmont office of Forever Dental. After a few days, support came in and installed eCentral so we can file electronic claims. That’s when the problems started. Specific Dentrix modules (notably, Treatment Planner and Chart) were running extremely slowly. Treatment Planner would take upwards of five minutes to open a patient chart. This made no sense: it’s a small (but growing!) second practice, and there is no reason Treatment Planner should require so much time.

Our setup is relatively simple:

  • Windows 7 running G6 Server
  • 5 Windows 7 workstations running G6 Clinical or G6 Frontoffice workstation
  • All 6 machines connected to a router and obtaining IP addresses with DHCP. Nothing fancy like static IPs, hosts files, etc.
  • LogMeIn Hamachi set up on all machines, so that we can Remote Desktop into those machines

After 2.5 hours with Dentrix, they stumbled upon a solution: disable link-local multicast name resolution (LLMNR). My theory is that Hamachi adds so many subnets as the network grows, and unless you have static IP addresses mapped to names in the hosts file, LLMNR requires each request to a name to timeout before finally identifying the proper name-to-IP-address mapping.

Yes, it worked, but even as I wrote the above, it felt wrong. So if someone out there knows what is really going on, please leave a comment!