anchor.diff:          description = "Specifies port number to connect on remote host.";
         };
   
  +      forwardAgent = mkOption {
  +        default = null;
  +        type = types.nullOr types.bool;
  +        description = ''
  +          Whether the connection to the authentication agent (if any)
  +          will be forwarded to the remote machine.
  +        '';
  +      };
  +
         forwardX11 = mkOption {
           type = types.bool;
           default = false;
  
positive.code:   cfg = config.programs.ssh;
  
    yn = flag: if flag then "yes" else "no";
  
    matchBlockModule = types.submodule ({ name, ... }: {
      options = {
  
negative.code:       default = false;
        type = types.bool;
        description = ''
          Whether the connection to the authentication agent (if any)
          will be forwarded to the remote machine.
        '';
      };
  
  