code: protected void startServer() throws Exception { // NOSONAR
  
          if (this.autoBind) {
              this.setTcpPort(NetworkUtils.findAvailablePort());
          }
  
          this.ldapServer = new LdapServer();
          this.ldapServer.setDirectoryService(getOuterRule().getDirectoryService());
          this.ldapServer.setTransports(new TcpTransport(this.getTcpPort()));
          this.ldapServer.start();
      }
docs: Starts the server on the configured listen address and tcp port (default localhost:10389) and assigns the {@link
  DirectoryService} provided by the {@link Directory} rule to it.
  
  @throws Exception
  if the server could not be started for various reasons, i.e. the directory service is not initialized or
  the port is already bound.