* -h: (Default.) Look up the remote host name in DNS to set the environment variable $TCPREMOTEHOST. * -H: Do not look up the remote host name in DNS; remove the environment variable $TCPREMOTEHOST. To avoid loops, you must use this option for servers on TCP port 53. * -p: Paranoid. After looking up the remote host name in DNS, look up the IP addresses in DNS for that host name, and remove the environment variable $TCPREMOTEHOST if none of the addresses match the client's IP address. * -P: (Default.) Not paranoid. * -l localname: Do not look up the local host name in DNS; use localname for the environment variable $TCPLOCALHOST. A common choice for localname is 0. To avoid loops, you must use this option for servers on TCP port 53. * -r: (Default.) Attempt to obtain $TCPREMOTEINFO from the remote host. * -R: Do not attempt to obtain $TCPREMOTEINFO from the remote host. To avoid loops, you must use this option for servers on TCP ports 53 and 113. * -t n: Give up on the $TCPREMOTEINFO connection attempt after n seconds. Default: 26.
