CARP with single static?



  • After a bout of questionable hardware leading to router failures, I'm seriously looking hard at pfsense's failover configuration. There's only one issue: My ISP. I'm on a shared T-3 in an apartment complex, and they don't have additional IP addresses available. The up side is that rather than running DHCP for the complex, we have static IP addresses assigned to each unit with a single CAT-5 drop as "feeder" for each unit.  I figured that I would use a pocket switch (5 port unmanaged switch) to "split" the WAN out and both devices would share the static IP via CARP.

    I've read the documentation for pfSense in regards to the failover configuration but I'm still wondering if it's possible to leave the two physical WAN ports unconfigured and use the static IP as the "shared" external IP between the WAN ports of the two routers.  Alternatively, is it possible to assign two bogus WAN IPs (nonroutable addresses, my guess?)?  Does the CARP traffic go over the dedicated link between the two routers or is there something else I'm not aware of?(probably the case).

    Thank you in advance.


  • Rebel Alliance Developer Netgate

    In order to do CARP, you need three IPs, there is no way around that currently.

    Even if you didn't do CARP on the WAN, you'd still need two – one for each unit.

    On pfSense 2.2 (next after we get 2.1 out), we might be able to do that if we pull in bits from newcarp/carpdev.



  • Hey Jimp:

    Thank you for your response. i appreciate the feedback.  I'll hold off for the 2.2 update and be sure to check it out.


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