First-hop redundancy protocol explained
A first hop redundancy protocol (FHRP) is a computer networking protocol which is designed to protect the default gateway used on a subnetwork by allowing two or more routers to provide backup for that address;[1] [2] in the event of failure of an active router, the backup router will take over the address, usually within a few seconds. In practice, such protocols can also be used to protect other services operating on a single IP address, not just routers.
Examples of such protocols include (in approximate order of creation):
- Hot Standby Router Protocol (HSRP) - Cisco's initial, proprietary standard developed in 1998[3]
- Virtual Router Redundancy Protocol (VRRP) - an open (albeit patent-encumbered) standard protocol based largely on Cisco's HSRP
- Common Address Redundancy Protocol (CARP) - patent-free, unencumbered alternative to Cisco's HSRP and the IETF's VRRP, developed in October 2003
- Extreme Standby Router Protocol (ESRP) - Extreme Networks' proprietary standard with fast failover and layer 2 protection
- Gateway Load Balancing Protocol (GLBP) - a more recent proprietary standard from Cisco that permits load balancing as well as redundancy
- Routed Split multi-link trunking (R-SMLT) - an Avaya redundancy protocol
- NetScreen Redundancy Protocol (NSRP) - a Juniper Networks proprietary router redundancy protocol providing load balancing
- Chassis Cluster Redundant Ethernet - a Juniper Networks proprietary Ethernet redundancy protocol, used on its SRX platform[4]
- Multi-active Gateway Protocol (MAGP) - a Mellanox proprietary protocol based on VRRP that allows active-active operation[5]
Notes and References
- Web site: First Hop Redundancy Protocol (FHRP). Cisco. en. 2019-06-05.
- Web site: First Hop Redundancy Protocols. gokhankosem. 2018-10-16. IpCisco. en-US. 2019-06-05.
- Web site: Cisco Protocols: HSRP, VRRP, GLBP. 2012-04-11. Petri. en-US. 2019-06-05.
- Web site: Chassis Cluster Redundant Ethernet Interfaces - TechLibrary - Juniper Networks. 2019-05-30. Juniper Networks. en-US. 2019-06-09.
- Web site: 1 March 2020. HowTo Configure MAGP on Mellanox Switches. community.mellanox.com.
