Using keepalived and VRRP to provide redundancy

Keepalived is a software package for Linux that provides load balancing and high-availability to Linux-based software and infrastructures.

The Virtual Router Redundancy Protocol, or VRRP, is a first-hop redundancy protocol that aims to provide high availability of a network's default gateway by allowing two or more routers to provide backup for this address. If the active router fails, a backup router takes over the address within a brief period of time. VRRP is an open standard and is based on the proprietary protocol known as Hot Standby Router Protocol (HSRP) developed by Cisco.

Neutron uses keepalived, which utilizes VRRP, to provide failover between multiple sets of router namespaces.

VRRP groups

With VRRP, a group of routers can be configured to act as a single virtual router. Routers in the VRRP group elect a master to act as the gateway device, and hosts in the network only need to configure the virtual router to act as their default network...