title: Check TCP connection through Jenkins Shell
body: <p>To make sure there are no firewall issues, I need to check Jenkins connection with several ports on a remote host. I want to use shell commands in a Jenkins job. Jenkins runs on Linux.</p>
  <p>Tried by now: telnet, nc, nmap</p>
  <p>All three gave me &quot;not found&quot;.</p>
  <p>Any alternatives?</p>