Targeted Multicast Client Service Executable - tmcsvc.exe has very high CPU on all clients

Version 10

    Verified Product Versions

    Endpoint Manager 9.6Endpoint Manager 2016.xEndpoint Manager 2017.x

    Landesk Management Suite 2016 / version 10.0)is using a new service called "Self-electing subnet services" (SESS): Self-electing subnet services

    Under some specific circumstances SESS service may cause very high CPU usage in client machines and servers, sometimes intensive multicast network traffic is experienced as well (even if you have not configured your Agents to use Multicast).

    Such incorrect behaviour can be identified by checking your Task Manager or Process Manager - you will see Targeted Multicast Client Service Executable (tmcsvc.exe) generating CPU load.







    Please first check the agent configuration settings for distribution and patch as 'tmcsvc.exe' can be used in multicast and peer-to-peer deployment, so on the agent settings set up for the agent configurations of the clients, you can disable "Attempt peer download" and "Use Multicast" (this can be found in Agent settings -> Distribution and Patch settings -> General settings -> Network Settings).

    It will update all the clients at the next daily vulnerability scan run on the clients where this settings is configured.


    If the above settings are not used (configured) then SESS can be deactivated in the agent "Client Connectivity Settings" set up on the agent(s) deployed on the clients.

    To do that, go to Tools -> Configuration -> Agent Settings and then click  'Client Connectivity' settings and open 'Self-electing subnet services' tab and uncheck box "Enable self-elect subnet service", click 'Save'.
    At the next daily vulnerability scan, on each computer having this settings, it will deactivate this option (alternatively you can create a task to deploy updated agent settings to the clients).


    Once this is done please check if the the CPU load from tmcsvc.exe has decreased on the agents.


    Additional information:

    You can also go in the Management Console -> Tools -> Configuration -> Self-electing subnet services -> Select Extended Device Discovery on both LAN/Wireless -> Right-click each subnet and select disable (by default SESS is disabled for wireless networks but enabled for wired networks).


    Some additional information on this topic can be find here: Agent 2016 - Targeted Multicast Client Service Executable - tmcsvc.exe very high CPU on all clients/servers


    This is fixed in 2018.1 and going forward.