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Layer-4 Health Check Daemon for IP Filter.

* Define as many clusters, with as many members as you need.
* Automatically adds and removes "ipnat" rules as needed.
* Flexible health check support, tcp-open, tcp-close, udp-open, udp-close, system.
* Simple scripting available for health checks in send/expect syntax with fnmatch pattern comparison
* Binary protocol supported in url-encoding style syntax (eg %0D)
* system() like execution of external commands available. (spawn your own health-check testers)
* Reload and restart leaving last-known-state available for less service impact.
* SSL supported for TCP testers.
* Optional IPF rules to sense RST return-packets for faster failure detection.

L4IP can use either direct ioctl, or system() style calls to the executable "ipnat". This first method is more efficient, but is very unportable. The second method should work on nearly all platforms and version of IP Filter that supports round-robin.

Available in CVS under "l4ip"

Earlier (latest stable) tarball is available here:


CVS Commitlog

Example configuration

Screen shot