How to disable ping thread on jenkins agent
In the web UI, from the home page, navigate to Manage Jenkins > Manage Nodes > Configure.  This page has all of the health checks that Jenkins performs to determine if an executor is up.  The check you are concerned about is called "Response Time".  You can disable the "Response Time" health check on this page.

From the help text on the same page:


  This monitors the round trip network response time from the master to the agent, and if it goes above a threshold repeatedly, it marks the agent offline.
  
  This is useful for detecting unresponsive agents, or other network problems that clog the communication channel. More specifically, the master sends a no-op command to the agent, and checks the time it takes to get back the result of this no-op command.