Free balanceng script

Major Features:

1. Layer 2 (Ethernet) "switching engine" based software load balancer.
2. Running under Linux (Using the PF_PACKET socket API) and Solaris (STREAMS/DLPI API).
3. Backup targets (hosts) specifiable in case of failure of all primary targets.
4. "Alert" and "Upalert" notification script interface.
5. Direct Server Return (DSR) operation support.
6. Unchanged client addresses on IP-level.
7. Small, very fast and reliable.
8. Simple to implement and administer.
9. Simple "init script style" arguments like "start", "stop" and "status" (and "control" for interactive configuration and control ).
10. Interactive communications mode with command line editing.
11. Pcap packet dumping with automated dumpfile rotation (e.g. to implement a "transparent forensic logging bridge").
12. Multi-Node High Availability capability using standard VRRP (Virtual Router Redundancy Protocol).
13. "All service load balancing" based on client IP address allows generic load balancing independent of specific ports.
14. SNMP support integrating into Net-SNMP with the BalanceNG MIB.
15. Up to 128 parallel instances (fully independent BalanceNG load balancers) on the same host machine.
16. Up to 1024 load balancing target servers (hard limit) per instance.
17. Up to 512 virtual servers (hard limit) per instance.
18. NAT state replication between master and backup node.
19. VRRP tracking supported to allow automatic resource tracking and failover.