HSRP vs VRRP vs GLBP Protocols

HSRP, VRRP, and GLBP all are First Hop Redundancy Protocols and network-layer protocols which are used to provide redundancy in the network. The main purpose of them is to provide redundancy to the default gateway in a LAN environment.

Hot Standby Router Protocol (HSRP) is a CISCO proprietary protocol, that provides a mechanism that is designed to provide support to non-disruptive failover of IP traffic in peculiar circumstances. Here in HSRP, two or more routers give an illusion of a virtual router. HSRP permits you to configure two or more routers as standby routers and only one single router as an active router at a time. Every router in a single HSRP group shares a single MAC address and IP address, which provides a default gateway to the local network. The Active router does the work of forwarding the traffic. If it fails, the Standby router makes up for it taking all the responsibilities of the active router and forwards the traffic.

Virtual Router Redundancy Protocol (VRRP) VRRP is an open standard IEEE protocol, which provides redundancy in a network. It eradicates the single point of failure inherent from the static default routed environment. It is a network layer protocol with protocol number-112. The number of routers in a group acts as a virtual logical router that acts as a default gateway of all the local hosts. If any of the routers goes down, other group members can take place for the responsibilities for forwarding the traffic.

Gateway Load Balancing Protocol (GLBP) Gateway Load Balancing Protocol (GLBP) is a Cisco proprietary protocol that is one of FHRP that provides redundancy like others in addition to it, it provides load balancing as well. It can perform functions like load balancing over multiple routers using single virtual IP address and multiple virtual Mac address.

One of the main differences is that VRRP is industry-standard while HSRP and GLBP are Cisco-proprietary protocols. VRRP and HSRP distribute themselves over a single layer 3 ethernet switch or a router to be the active one in a group, whereas GLBP can target up to four routers by configuring load balancing schemes.

The best one to select is really a matter of the type of equipment at your disposal, network design complexity, or sometimes personal preference. 

Following is a table of comparisons between VRRP, HSRP, and GLBP:

Basis of Comparison	VRRP	HSRP	GLBP
Standard	Open IEEE Standard	Cisco’s Proprietary Protocol	Cisco’s Proprietary Protocol
First Hop Redundancy Protocol	FHRP	FHRP	FHRP
Timers	Default Hello – 1 Sec Hold Time – counted automatically and can’t be configured.	Default Hold/Dead Time – 10 Secs  Default Hello – 3 Secs	Default Hold/DeadTime – 10 Secs
RFC	5798	2281	No RFC
IPv6	No support for IPv6 on the original VRRP, VRRPv3 now supports it.	Supports IPv6	Supports IPv6
Virtual IP	Virtual IP could be the same as physical IP	Configure separate IP for the Virtual.	Configure separate IP for the Virtual.
Preemption	Enabled by default	Not enabled by default	It is not enabled by default for AVGs.
Router Roles	It follows the concept of master and backup router  roles	Its router roles are – Active and Standby GLBP	Router roles like – AVG, AVF and AVS
Load Balancing	Not Supported – Sharing can be done by configuring  single subnet/Interface of multiple groups.	Load Balancing not Supported – Sharing can be done for the cause .	Load Balancing Supported -3 Load Balancing Schemes  like Round-Robin (Default), Weighted, and Host-Dependent
Virtual MAC Address	0000.5e00.01xx – here XX is the VRRP group number in hex	0000.0c07.acXX – here XX is the HSRP group number in HEX	0007.b4XX.XXYY here XX.XX = 6 zero bits(empty) and 10 bits for the Group number.
Sample Configuration	> ip address ip-address mask > vrrp group-description text	> standby-[group]-ip {virtual-ip} > standby-[group]-timers {hello}	> glbp-group-ip [ip-address [secondary] > glbp-group timers [nsec ]hellotime [nsec ] holdtime