Redundancy is a common point for today’s High Available Networks. First Hop Redundancy is one of the redundancy mechanisms that provide high available and always on networks. These redundancy mechanims provide redundancy by providing multiple alternative paths to the destinations and ensure single point of failure avoidance.
The main operation of these First Hop Reundancy mechanims are selecting a key device as Active and send the traffic through it. Beside, provide one more available Backups and turn the traffic flow throuh it during a failure. By duing this, if a single device has problems, traffic is not lost and continues to flow through another backup device.
By the way, a Virtual IP address is used and shared in these mechanims. So, as the gateway, this Virtual IPs are used and the traffic flows independent from any device and physical address.
There are three wellknown First Hop Redundancy Protocols (FHRPs). These are
Another protocol, VRRP, is a Standard Based protocol. you can use this protocol in all vendor’s devices, like Juniper, Nokia and Huawei.