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tacos_tacos_tacos
Asked: 2013-03-09 13:28:36 +0800 CST

Does two pfsense + CARP necessarily require two WAN IP?

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I am looking to setup CARP following this guide across two pfSense firewalls.

I have setup CARP before on a WAN link with a big IP space, so allocating a distinct WAN IP per each device (as shown in the guide) was palatable.

Now, I am trying to do the same, but only one WAN IP is available per link.

Is there a way to use only one WAN IP?

Edit: What if you have the following configuration? (would this work?)

  • WAN1: WAN IP 1.2.3.4, local IP 192.168.10.1
  • WAN2: WAN IP 1.2.3.5, local IP 192.168.20.1
  • pf1: On interface WAN1, local IP 192.168.10.10; on WAN 2, local IP 192.168.20.10;
  • pf2: On interface WAN1, local IP 192.168.10.11; on WAN 2, local IP 192.168.20.11;
  • On both pf1 and pf2, monitor IP set to the ISP-appropriate value
  • VIP on 192.168.10.100, 192.168.20.100
pfsense

4 Answers

  1. Best Answer

    No, carp requires three WAN IPs.

    • 5

  2. It does not, it depends on your Setup. I have a working solution with 1 IP. The Slave just uses the Master as a gateway.

    • 4

  3. CARP is like VRRP, HSRP and most other routing redundancy protocols, you must have 3 static IPs in the same subnet.

    That may change at some point in the future, but it's true for the time being.

    • 3

  4. this topic has been requested as a feature in the pfsense bugtracker https://redmine.pfsense.org/issues/3859 and also issue 4597

    and in this post https://forum.pfsense.org/index.php?topic=87546.msg495163#msg495163

    it seems possible but you have to work around the webGUI

    • 0