L4ip

L4ip is a powerful software daemon that can be used to extend IPFilter's straightforward round-robin L4 load balancing by incorporating health checks. With L4ip, you no longer need to worry about monitoring or dynamically adding and removing ipnat rules in your kernel.

One of the most significant advantages of L4ip is that it offers flexible health check support for TCP, UDP, and even system()-style executions. You can use send/expect scripts, SSL connections, and other options to ensure that your system remains healthy at all times.

Some of the key features of L4ip include the ability to define as many clusters as necessary, with as many members as required. Additionally, L4ip automatically adds and removes "ipnat" rules as needed.

The software also offers simple scripting options for health checks in send/expect syntax, complete with fnmatch pattern comparison. You can even use a binary protocol supported in url-encoding style syntax, and the software allows system()-like execution of external commands to spawn your own health-check testers.

L4ip's reload and restart feature means that the last-known-state is always available, minimizing service impact. SSL is supported for TCP testers, and there are optional IPF rules to sense RST return-packets for faster failure detection.

The latest release of L4ip comes with Solaris SMF example files and a "proxy" command for protocols such as FTP and IPSec. If you're looking for a reliable and comprehensive software daemon for load balancing with health check capabilities, L4ip is the perfect solution.