HSRP vs VRRP vs GLBP

 10:40:00 AM  GLBP , HSRP , LOAD BALANCING , VRRP

ProtocolFeatures		HSRP (Hot Standby Router protocol)	VRRP (Virtual Redundancy Router Protocol)	GLBP (Gateway Load Balancing Protocol)
Router role		- 1 active router.- 1 standby router.- 1 or more listening routers.	- 1 master router.- 1 or more backup routers.	- 1 AVG (Active Virtual Gateway).- up to 4 AVF routers on the group (Active Virtual Forwarder) passing traffic.- up to 1024 virtual routers (GLBP groups) per physical interface.
		- Use virtual ip address.	- Can use real router ip address, if not, the one with highest priority become master.	- Use virtual ip address.
Scope		Cisco proprietary	IEEE standard	Cisco proprietary
Election		Active Router: 1-Highest Priority 2-Highest IP (tiebreaker)	Master Router: (*) 1-Highest Priority 2-Highest IP (tiebreaker)	Active Virtual Gateway: 1-Highest Priority 2-Highest IP (tiebreaker)
Optimization features	Tracking	yes	yes	yes
	Preempt	yes	yes	yes
	Timer adjustments	yes	yes	yes
Traffic type		224.0.0.2 – udp 1985 (version1) 224.0.0.102-udp 1985 (version2)	224.0.0.18 – IP 112	224.0.0.102 udp 3222
Timers		Hello – 3 seconds	Advertisement – 1 second	Hello – 3 seconds
		(Hold) 10 seconds	(Master Down Interval)3 * Advertisement + skew time	(Hold) 10 seconds
			(Skew time)(256-priority) / 256
Load-balancing functionality		- Multiple HSRP group per interface/SVI/routed int.	- Multiple VRRP group per interface/SVI/routed int.	Load-balancing oriented- Weighted algorithm.- Host-dependent algorithm. - Round-Robin algorithm (default).
		Requires appropriate distribution of Virtual GW IP per Clients for optimal load-balancing.(generally through DHCP)	Requires appropriate distribution of Virtual GW IP per Clients for optimal load-balancing.(generally through DHCP)	Clients are transparently updated with virtual MAC according to load-balancing algorithm through ARP requesting a unique virtual gateway.

* If the group VRRP Virtual IP on the master (higher priority) is the real IP configured on a different VRRP (Backup with lower priority) IOS will manage to make the VRRP router with the real IP, the master, by setting its priority to 255, knowing that the configurable range is [1-254].