tcplist

tcplist - list tcp connections to/from this machine

SYNOPSIS

tcplist [ -n ] [ -N ] [ -T ] [ -s ] [ -v ] [ -V ] [ -f filename ] [ -t timeout ]

DESCRIPTION

Tcplist lists all the TCP connections to or from the machine it is run on. If any of the remote machines are running Ident-compilant servers, this is queried, and the results listed for each connection. Output is by default in "user@address:portnum user@address:portnum" format.

Ident queries are done using non-blocking I/O, for performance.

OPTIONS

-T: Report results in tabular format, with header. This format is probably easier to read, but harder to parse.
-n: Don't resolve hostnames, but use host IP addresses instead.
-N: Don't resolve port names. Use port numbers instead.
-s: Show TCP servers running on this machine as well as established connections.
-v: Verbose mode: give a running commentary of what is being done.
-V: Print version information and exit.
-f filename: Assume the hosts listed in the specified file are not running Ident servers, and should not be queried. Listing terminal servers, X terminals, PC's, and similar machines in this file can significantly speed up tcplist in some environments.
-t timeout: Use the specified timeout for Ident queries. The default timeout is 30 seconds.

FILES

/etc/services, /etc/hosts

HISTORY

Written by John DiMarco at the University of Toronto, CSLab

BUGS

The kernel's tables can change while tcplist is examining them, creating incorrect or partial displays.

Excessively long strings returned by Ident servers may be truncated.

If an Ident server doesn't respond within the timeout, it is presumed to be down. If the machine is very slow, remote, or congested, it may in fact be up. The shorter the timeout, the more likely this will be.