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Comment by mwpmaybe | Hacker News Reader

> Corosync/Pacemaker: Designed for reliability. Leave VRRP where it belongs (I'm looking at you keepalived).

I just set up a floating IP address for the first time today and went with keepalived. Why would you recommend Corosync/Pacemaker over keepalived?

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If you need just the floating IP address, keepalived is fine.

I'm mostly bitter from spending days tracking down a race condition stemming from its notification scripts, which wasn't really keepaliveds fault per se. But if you need to start/move/constraint/notify anything along with the IP, or require sub-second failover, Corosync/Pacemaker is a far better choice.

However due to their complexity, for just a floating IP address, keepalived is unfortunately the best option for Linux (I usually have OpenBSD in that spot).

Thanks for the explanation. Out of sheer curiosity (and because I run BSD-based pfSense and FreeNAS at home), how do you handle floating IPs and that sort of thing on OpenBSD?

OpenBSD invented a similar protocol to VRRP called CARP back when VRRP was patent-encumbered[0].

Configuring it is deceptively simple: just create an interface with ifconfig called "carpN", specifying VID, password and IP address[1].

You can also make it load-balance traffic between your carp hosts if desired[2].

Give it a go for your next firewall/server build :)

0: https://en.wikipedia.org/wiki/Common_Address_Redundancy_Prot...

1: https://www.openbsd.org/faq/pf/carp.html

2: http://man.openbsd.org/OpenBSD-current/man4/carp.4

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