Some routers support detailed logging via Syslog.  Syslog is an industry standard protocol used for capturing log information for devices on a network, usually via UDP Port 514.

Syslog support is included in Unix and Linux based systems, but is not included in Windows and MacOs.  However, there are third-party applications available to add this capability to your system.  
The following applications run on Windows unless otherwise noted:

  • TriAction Syslog Daemon (Thnx Bill Pye!)
    30 day free trial, $30 license
    Has rule engine for filtering and rerouting of messages. Can also react to events and trigger or execute an external program.

  • Kiwi [Win95,98,NT, 2000]
    “Basic” features are free, more advanced features require $49 registration.
    Supports multiple TCP syslog connections and Cisco PIX firewall. “Basic” features are pretty comprehensive! Minimizes nicely to the system tray.
    6.2.9 adds SNMP trap logging capability & other features

  • Microtik syslog daemon [Win95,98,NT,2000]
    This is a networking hardware manufacturer from Latvia. It is a nice and compact standard syslog daemon.

  • Netlogger [MacOs]
    $10 Shareware
    A syslog client that will let your Mac accept log files from a syslog server
    Download here

  • SL4NT [WinNT4, Win2000 only]
    60 day free trial, $95 for single user license
    Download here

  • Syslog Daemon [Windows]
    Free syslog daemon written in Visual Basic 5 by Eckhart von dem Berge. Installer includes all VB modules.
    (The installer talks to you in German, but you can figure out what to do.  Docs are in English. Thanks to Alan Ridgeway for the tip!)
    Download here

  • Syslogd [Macintosh]
    $20 shareware, requires StuffIt Expander to open.
    An implementation of the UNIX program by the same name for the Mac OS. It’s a daemon that accepts messages from other applications and the network, and writes them out to system wide log files. (Thanks to reader Wolfgang Husmann for letting us know about it.)
    Download here
  • 3COM has a free syslog daemon