A first hop redundancy protocol (FHRP) is a
computer networking
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections ar ...
protocol which is designed to protect the
default gateway used on a
subnetwork
A subnetwork or subnet is a logical subdivision of an IP network. Updated by RFC 6918. The practice of dividing a network into two or more networks is called subnetting.
Computers that belong to the same subnet are addressed with an identica ...
by allowing two or more
routers to provide backup for that address; 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
An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...
, not just routers.
Examples of such protocols include (in approximate order of creation):
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Hot Standby Router Protocol (HSRP) -
Cisco
Cisco Systems, Inc., commonly known as Cisco, is an American-based multinational corporation, multinational digital communications technology conglomerate (company), conglomerate corporation headquartered in San Jose, California. Cisco develo ...
's initial, proprietary standard developed in 1998
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Virtual Router Redundancy Protocol (VRRP) - an open (albeit patent encumbered) standard protocol
*
Common Address Redundancy Protocol (CARP) - patent-free unencumbered alternative to Cisco's HSRP developed in October 2003
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Extreme Standby Router Protocol
Extreme may refer to:
Science and mathematics Mathematics
*Extreme point, a point in a convex set which does not lie in any open line segment joining two points in the set
*Maxima and minima, extremes on a mathematical function
Science
*Extremop ...
(ESRP) -
Extreme Networks
Extreme Networks is an American networking company based in San Jose, California. Extreme Networks designs, develops, and manufactures wired and wireless network infrastructure equipment and develops the software for network management, policy, a ...
' proprietary standard with fast failover and also
layer 2
The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between nodes on a network segment across the physical layer. The data link layer ...
protection
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Gateway Load Balancing Protocol (GLBP) - a more recent proprietary standard from Cisco that permits
load balancing as well as redundancy
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Routed Split multi-link trunking (R-SMLT) - an
Avaya
Avaya Holdings Corp., often shortened to Avaya (), is an American multinational technology company headquartered in Durham, North Carolina, that provides cloud communications and workstream collaboration services. The company's platform inc ...
redundancy protocol
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NetScreen Redundancy Protocol
NetScreen Technologies was an American technology company that was acquired by Juniper Networks for US$4 billion stock for stock in 2004.
NetScreen Technologies developed ASIC-based Internet security systems and appliances that delivered high per ...
(NSRP) - a
Juniper Networks
Juniper Networks, Inc. is an American multinational corporation headquartered in Sunnyvale, California. The company develops and markets networking products, including routers, switches, network management software, network security products, ...
proprietary router redundancy protocol providing load balancing
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Chassis Cluster Redundant Ethernet
A chassis (, ; plural ''chassis'' from French châssis ) is the load-bearing framework of an artificial object, which structurally supports the object in its construction and function. An example of a chassis is a vehicle frame, the underpart ...
- a Juniper Networks proprietary Ethernet redundancy protocol, used on its SRX platform
*
Multi-active Gateway Protocol (MAGP) - a
Mellanox
Mellanox Technologies Ltd. ( he, מלאנוקס טכנולוגיות בע"מ) was an Israeli-American multinational supplier of computer networking products based on InfiniBand and Ethernet technology. Mellanox offered adapters, switches, softwa ...
proprietary protocol based on VRRP that allows active-active operation
References
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Internet protocols