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I've just bought a dedicated server in and they are sending me some warnings in email that I haven't configured my IP Failover address correctly and they're going to block this failover within 24 hours if I won't take any actions.

So, the question is, how should IP Failover be configured properly in FreeBSD 8.2?

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What kind of failover (CARP between two machines? Multiple NICs failing over if the link goes down?) – voretaq7 Dec 14 '11 at 20:19
I think this one: Multiple NICs failing over if the link goes down. – Cyclone Dec 15 '11 at 9:56
The answer to that question substantially changes the answer (multiple NICs in one box is lagg(4) -- Link aggregation (see James' answer). Multiple machines passing around one address to make sure stuff stays up when one machine goes down is carp(4) - the Common Address Redundancy Protocol. For extra redundancy you can even combine the two :-) – voretaq7 Dec 15 '11 at 16:28
up vote 2 down vote accepted

Have a look at lagg(4) (FreeBSD Handbook entry). The ifconfig commands you need are:

ifconfig em0 up
ifconfig em1 up
ifconfig lagg0 laggproto failover laggport em0 laggport em1 netmask

(Substitute em0, em1, IP address and netmask as appropriate.)

The equivalent for rc.conf is:

ifconfig_lagg0="laggproto failover laggport em0 laggport em1 netmask"
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+1 for linking to the handbook, source of all FreeBSD knowledge (and a pretty darn good general *NIX reference) – voretaq7 Dec 15 '11 at 16:27
Thank you for the handbook also! – Cyclone Dec 15 '11 at 19:09

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