The port 135/TCP…. is used by…Microsoft RPC Endpoint Mapper…. to direct customers to the CPR services available under Windows. It intervenes in particular in uses such as WMI or DCOM, whose exchanges can then continue on dynamic RPC ports which, it is also necessary to take into account when diagnosing…
What is Harbour 135 for?….
The port 135/TCP…. Microsoft RPC Endpoint Mapper. A CPR client can first contact this entry point to find out which one of the requested RPC service is being listened to. The application conversation can then continue on a…. dynamic PRC port…. different from 135….
This is a key point in the diagnosis: passing a 135 test does not prove that WMI, DCOM or any other RPC service will work from end to end if the necessary dynamic EPs are filtered….
Transport Protocol
TCP
Safety precautions
Should we open this port in the firewall?
Port 135 is part of the RPC Windows infrastructure and must be limited to networks and machines that actually need it. Avoid direct exposure to the Internet. For a Service Administration, filter sources and destinations and take into account the dynamic RPC ports required by the service;…. Open 135 alone or open a very wide range without identified need are two bad approaches…
How do I check this port?
On the Windows server, check the listen with…. Get-NetTCPConnection -LocalPort 135 -State Listen or…. netstat -ano | findstr :135. From the client,…Test-NetConnection SERVER -Port 135 allows control of the, establishment, tactile….
- Confirm that 135/TCP is reachable….
- Identify the failed CPP application and reproduce its appeal….
- If 135 works but the application fails, check the RPC dynamic range allowed between the two hosts….
- Review the Windows logs and firewall rules associated with the service concerned….
FAQ — port 135 / Microsoft RPC Endpoint Mapper….
Why is port 135 open when my RPC call fails?…
The client can reach the droppoint Mapper out of 135 and then be redirected to a dynamic RPC-based EP which is filtered or unavailable…
Is port 135 sufficient for WMI or DCOM?….
Not always. These uses may depend on dynamic RPC after initial discovery on 135….
Should port 135 be published on the Internet?…
Direct exposure is usually not required for Windows administration. Prefer controlled network access, VPN or other secure administration mechanism…