Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have 2 pfSense servers (the new and the old one) which are used as routers, DHCP and DNS servers. I want to configure the old one as a backup of the new one. It means that when all is ok, all the traffic is managed by the new one. And if the new goes down, I want the old managing the traffic in real time.

    Main internet               Backup internet
    (fiber)                     (ADSL)         

    ^                           ^              
    |                           |              
    |            +--------------+              
    |            |              |              
+---+------------+---+    +-----+------------+ 
|                    |    |                  | 
|  Main pfSense      |    |  Backup pfSense  | 
|  server            |    |  server          | 
|                    |    |                  | 
+---------+----------+    +----+-------------+ 
          |        |  
          |                    |               
          |                    |               
          |                    |               
|                                            | 
|             Ethernet switch                | 
|                                            | 

I want to known if it is possible and where to do that (at the pfSense level or at the switch level)?

share|improve this question
up vote 9 down vote accepted

Yes, this is absolutely possible. In fact, the pfSense wiki has an entire page dedicated to this topic.

In short, you'll use CARP VIPs so to move your gateway address between routers and then use pfSense's XMLRPC sync to synchronize config between the two devices.

In an ideal setup, you'd have both of your internet circuits connected to each router. This gives you the highest degree of flexibility and resiliency, so consider changing your architecture to consider this.

share|improve this answer
Indeed, CARP is all I need. Thanks – jml Jun 12 '14 at 12:55

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.