First Hop Redundancy protocol comparison (HSRP,VRRP,GLBP)

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		RFC 2281	RFC 3768	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.

Configuration Example on Cisco Router:

• HSRP Configuration

interface FastEthernet0/0
ip address 10.0.1.2 255.255.255.0
standby version {1 | 2}
standby 1 ip 10.0.1.1
standby 1 timers <hello> <dead>
standby 1 priority <priority>
standby 1 preempt
standby 1 authentication md5 key-string <password>
standby 1 track <interface> <value>
standby 1 track <object> decrement <value>

• VRRP Configuration

interface FastEthernet0/0
ip address 10.0.1.2 255.255.255.0
vrrp 1 ip 10.0.1.1
vrrp 1 timers {advertise <hello> | learn}
vrrp 1 priority <priority>
vrrp 1 preempt
vrrp 1 authentication md5 key-string <password>
vrrp 1 track <object> decrement <value>

• GLBP Configuration

interface FastEthernet0/0
ip address 10.0.1.2 255.255.255.0
glbp 1 ip 10.0.1.1
glbp 1 timers <hello> <dead>
glbp 1 timers redirect <redirect> <time-out>
glbp 1 priority <priority>
glbp 1 preempt
glbp 1 forwarder preempt
glbp 1 authentication md5 key-string <password>
glbp 1 load-balancing <method>
glbp 1 weighting <weight> lower <lower> upper <upper>
glbp 1 weighting track <object> decrement <value>