Server Load Balancing

With the server load balancing function you can distribute incoming connections (e.g., SMTP Simple Mail Transfer Protocol or HTTP Hypertext Transfer Protocol traffic) to several servers behind the gateway. Balancing is based on the source IP address with a persistence time of one hour. If the interval between two requests from the same source IP Internet Protocol address exceeds that interval, the balancing is redecided. The traffic distribution is based on a simple round-robin algorithm.

All servers from the server pool are monitored either by ICMP Internet Control Message Protocol ping, TCP Transmission Control Protocol connection establishment, or HTTP/S requests. In case of a failure the affected server is not used anymore for distribution, any possible source IP persistence is overruled.

Note – A return code of HTTP/S requests must either be 1xx Informational, 2xx Success, 3xx Redirection, or 4xx Client Error. All other return codes are taken as failure.