Not quite. CARP (VRRP in Ciscoese) has two (or more) systems capable of presenting the same IP address and they agree amongst themselves which gets to be the m

Not quite. CARP (VRRP in Ciscoese) has two (or more) systems capable of presenting the same IP address and they agree amongst themselves which gets to be the master through a multicast based advertizing system. Generally each system will be near clones of each other and be capable of doing the full job themselves. I have a pair of rather large pfSense systems running CARP as my office routers. I can update the secondary, test it, fail over the CARP addresses and fifty IPSEC tunnels, five internet connections, 10 OpenVPN servers along with rather a lot of clients, five OpenVPN clients, 30 odd internal VLANs and all the states for the above along with many NAT inbound and outbound sessions will seamlessly switch over thanks to PFSYNC. Even voice calls don't drop - you might notice a sub second wobble if someone is talking at the wrong moment. Rinse/repeat for the other one. BGP, RIPx, OSPF and co. are routing protocols that deal with the route your connections take through a network. There are also things like LACP/LAG for layer two redundancy. You can even play games with DNS round robin and of course reverse proxies. CARP is one tool in the box for coping with failures and maintenance - there are lots of others, each with advantages and disadvantages. That's what makes the job interesting 8)