Is it possible to set up CARP with 1 ip from an ISP?

Question

FreeBSD

Good day!
I set up ip telephony. Received from the provider sip trunk and internal ip in the provider's SIP vlan as 10.0.0.5/30.
Plugging this ip directly into the PBX is not an option, because. ehternet port is only 1, and it does not support vlan. In addition, communication with internal sip-clients goes through the same port. At the same time, there are 2 routers on FreeBSD operating in failover mode using carp (so far, each has its own external ip). Setting up NAT on one of them is generally not a problem and it already works, the fact is that there is no failover for the sip network. The question is - is it possible to configure carp for ip with the 30th mask, and if not, what other options are there in this situation?
Thanks in advance.

Answer 1

For CARP to work, three addresses are needed: one for each gateway and one common address on behalf of which communication takes place.