pfsync is a

computer protocol A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchroniza ...

used to synchronise

firewall states In computing, a stateful firewall is a network-based firewall that individually tracks sessions of network connections traversing it. Stateful packet inspection, also referred to as dynamic packet filtering, is a security feature often used in ...

between machines running Packet Filter (PF) for

high availability High availability (HA) is a characteristic of a system which aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period. Modernization has resulted in an increased reliance on these systems. Fo ...

. It is used along with

CARP Carp are various species of oily freshwater fish from the family Cyprinidae, a very large group of fish native to Europe and Asia. While carp is consumed in many parts of the world, they are generally considered an invasive species in parts of ...

to make sure a backup firewall has the same information as the main firewall. When the main machine in the firewall cluster dies, the backup machine is able to accept current connections without loss.

References

External links

PF: Firewall Redundancy with CARP and pfsync ''(OpenBSD PF FAQ)''

pfsync(4) man-page in OpenBSD, FreeBSD and NetBSD

sys/net/if_pfsync.h in OpenBSD

sys/net/if_pfsync.c in OpenBSD
Internet protocols High-availability cluster computing BSD software OpenBSD FreeBSD NetBSD Firewall software {{network-software-stub

See also

References

External links