Can't add new CARP VIP with pfSense 2.1
I've recently upgraded to pfSense 2.1. I have a CARP / NAT failover setup. Back on pfSense 1.2, I could create a new CARP VIP for each public IP Adress without problems.
Now, if I try to create a new Entry, I get the error:
"The /31 and /32 subnet mask are invalid for CARP IPs."
Settings are: "Type: CARP, Interface WAN, IP-Adresse 195.X.X.X / 32"
I also can't change the prev entrys. I used to create a seperate entry for every host. Why I can't do this anymore?
Well which part isn't clear exactly? :)
You can't use subnet with less than 3 usable IPs in it - Node1, Node2, VirtuapIP. Also the virtual IP should have subnet mask the same as the interface itself.
So, how can I add a carp single host address?
CARP is the way the virtual IP address sharing between two hosts works. If you don't have two hosts - you can't have CARP. Which means subnet with at least 3 available IPs is required.
CARP VIPs are always single host addresses. The subnet mask on a CARP VIP must match the parent subnet. So if you WAN is x.x.x.a/28, then your CARP VIP must be (for example) x.x.x.b/28 – it's still just one IP. It's not like proxy ARP where it makes a bunch of IPs if you pick a larger mask.