SwarmAgent communication failure


working on the 4.8 engine, I wanted to share the lighting building with a rendefarm.
After seeking for some explanations about SwarmAgent, I succeeded in the configuration for 4 stations.
Actual and old Workstations are together connected on the coordinator.
However, when trying to connect the renderfarm’s pcs, i’ve got a Ping error : Communication with the coordinator failed, job distribution will be disabled until the connection is established.
The configuration is exactly the same as my workstation, I’ve disabled the firewall, checked the network connection parameters and so on. The pcs are not seen through the coordinator.

The only difference between these render pcs and my workstation is that they only have a built-in graphic chipset (workstation has a quadroFX 4000).
Working under win7, bi-hexacore with hyperthreading enabled, 24GB RAM.

Any idea why these render pcs don’t wan’t to contact the coordinator ?
Thanks a lot.

Alright, it seems that installing all the needed windows updates solved the problem. The prerequisite package founded in the UE folders seems not to be up-to-date.
Good to know.