Explanation/Reference:
Explanation:
A comparison of the three First Hop Redundancy Protocols are listed below:
GLBP
HSRP VRRP
Protocol
(Gateway Load
(Hot Standby Router (Virtual Redundancy
Features
Balancing Pro-
protocol) Router Protocol)
tocol)
- 1 AVG (Ac-
tive Virtual
Gateway).- up
to 4 AVF
routers on the
- 1 active router.- 1 group (Active
- 1 master router.- 1
standby router.- 1 or Virtual For-
or more backup
more listening warder) passing
routers.
routers. traffic.- up to
Router role
1024 virtual
routers (GLBP
groups) per
physical inter-
face.
- Can use real router
- Use virtual ip ad- ip address, if not, the - Use virtual ip dress. one with highest pri- address.
ority become master.
Cisco propri-
Scope Cisco proprietary IEEE standard
etary
Active Virtual
Active Router: Master Router: (*) Gateway:
1-Highest Priority 1-Highest Priority 1-Highest Pri-
Election
2-Highest IP 2-Highest IP ority
(tiebreaker) (tiebreaker) 2-Highest IP
(tiebreaker)
Tracking yes yes yes
Optimization
Preempt yes yes yes
features
Timer ad-
yes yes yes
justments
Traffic type 224.0.0.2 udp 1985 224.0.0.18 IP 112 224.0.0.102 udp (version1) 3222
224.0.0.102-udp 1985
(version2)
Advertisement 1 Hello 3 sec-
Hello 3 seconds
second onds
(Master Down Inter-
Timers val)3 * Advertisement
(Hold) 10 sec-
+ skew time
(Hold) 10 seconds
onds
(Skew time)(256-pri-
ority) / 256
Load-balancing
oriented-
Weighted algo-
- Multiple HSRP - Multiple VRRP
rithm.- Host-de-
group per in- group per in-
pendent algo-
terface/SVI/routed terface/SVI/routed
rithm.
int. int.
- Round-Robin
algorithm (de-
fault).
Load-balancing functional-
Clients are
ity
transparently
updated with
Requires appropriate Requires appropriate
virtual MAC
distribution of Virtual distribution of Virtual
according to
GW IP per Clients for GW IP per Clients for
load-balancing
optimal load-balanc- optimal load-balanc-
algorithm
ing.(generally through ing.(generally through
through ARP
DHCP) DHCP)
requesting a
unique virtual
gateway.
Reference: http://cciethebeginning.wordpress.com/2008/08/23/router-high-availability-protocol- comparison-2/