pfsync

{{Short description|Computer firewall protocol}}

{{refimprove|date=May 2016}}

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{{infobox software}}

pfsync is a computer protocol{{cite web |url=http://bxr.su/o/etc/protocols |title=/etc/protocols |publisher=OpenBSD |website=BSD Cross Reference |quote="pfsync 240"}}{{cite web |url=http://bxr.su/o/sys/net/if_pfsync.h |title=/sys/net/if_pfsync.h |publisher=OpenBSD |website=BSD Cross Reference}} used to synchronise firewall states between machines running Packet Filter (PF) for high availability. It is used along with CARP 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.{{cite web

|url= http://www.onlamp.com/lpt/a/4767

|title= OpenBSD PF Developer Interview

|author= Federico Biancuzzi

|website= ONLamp |publisher= O'Reilly Media

|date= 2004-04-15 |archive-url= https://web.archive.org/web/20040508140530/http://www.onlamp.com/lpt/a/4767

|access-date=2019-03-20

|archive-date= 2004-05-08

}}{{cite web

|url= http://www.onlamp.com/lpt/a/4839

|title= OpenBSD PF Developer Interview, Part 2

|author= Federico Biancuzzi

|website= ONLamp |publisher= O'Reilly Media

|date= 2004-05-06 |archive-url= https://web.archive.org/web/20040619005622/http://www.onlamp.com/lpt/a/4839

|access-date=2019-03-20

|archive-date= 2004-06-19

}}