Highly available routers can be created and managed using the same router command set discussed in the previous chapter. Neutron L3 agents are responsible for configuring the routers in a VRRP group, and the routers are left to elect a master router and implement their respective keepalived configuration based on their master or backup state at that time.
While HA routers provide a level of redundancy over their standalone counterparts, they are not without their drawbacks. A single node hosting a master router is still a bottleneck for traffic traversing that router. In addition, if the network used for dedicated VRRP traffic between routers experiences a loss of connectivity, the routers can become split-brained. This can cause two or more routers to become master routers and potentially cause ARP and MAC flapping issues in the network. Connection tracking between routers...