High Availability (HA)

High Availability (HA) enables you to deploy groups of Screens together in situations in which the connection between a protected inside network and an insecure outside network is critical. At any time, one member of the HA cluster is the active Screen, which performs packet filtering, network address translation, logging, and encryption or decryption of packets travelling between the inside and outside networks. The other members of the Screens, receive the same packets, perform the same calculations as the active Screen, and mirror the state of the active Screen, but they do not forward traffic. When an active Screen fails, the passive Screen that has been running the longest takes over as the active Screen within 15 seconds. During this time (before the passive Screen takes over), no traffic will go through the HA cluster.

HA cluster, the passive

SunScreen provides flexible logging of packets. This means that each primary and secondary Screen can keep a log of its traffic. Logs of the packets are kept on the Screen that passed or rejected the packets.