Port Requirements for IIS Applications Pools

Be sure the following ports are open on the IIS server to allow discovery of IIS application pools and related accounts:

• Port 135 (TCP) for inbound communication with the RPC endpoint mapper program.
• A custom inbound firewall rule to allow communication for the DllHost.exe process on all RPC Dynamic Ports.
• Port 139 (TCP) for file and printer sharing (NB-Session-In) inbound communication if the operating system is Windows Server 2016.

For more information about configuring firewall rules for discovery, see System Discovery Prerequisites