This document provides information on various IP routing protocols: - It describes the characteristics and types of IP services, including first hop routing protocols (FHRP) like HSRP, VRRP, and GLBP. - VRRP and GLBP provide router redundancy and load balancing. VRRP supports up to 255 groups while GLBP supports up to 1024 virtual routers. - HSRP establishes a default gateway with one active and one standby router. It is Cisco proprietary while VRRP is a multivendor standard.

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IP Services

2. IP service characteristics:
 Deploy an IP network with basic end-to-end IP connectivity
 Manage their IP addressing requirements from a central location
 Control the IP addressing scheme used throughout their network
 Provide redundancy at major network connection points
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3. Types of IP services
1. FHRP [ First Host Routing Protocol ]
2. HSRP [ Hot Standby Routing Protocol ]
3. VRRP [ Virtual Router Routing Protocol ]
4. GLBP [ Gateway load Balancing Protocol ]
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4. VRRP
 VRRP or virtual router redundancy protocol provides router
or switch interfaces failover and failback facility for
seamless operation of a network. VRRP almost similar to
HSRP in terms of operations and functions, but with a few
added features such as VRRP supports up to 255 groups.
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5. VRRP
characteristics:-
 Switch with the highest priority will be the master switch. If you configure all the
switches with the same priority value, then the switch with highest real IP
becomes the master.
 Non-master switches will learn the timing from the master. To configure timers
in non-master switch use the vrrp (group-number) timers learn command
 If you set the real IP as the vrrp id then the switch or router with that IP
becomes the master of that group
 VRRP is a multivendor protocol, unlike HSRP which is Cisco proprietary
protocol.
 VRRP can only track objects, not interfaces
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6. Benefits of VRRP:-
 Support for IPv4 and IPv6
 Multiple Virtual Devices
VRRP supports up to 255 virtual devices (VRRP groups) on a device
physical interface, subject to restrictions in scaling. Multiple virtual device
support enables you to implement redundancy and load sharing in your
LAN topology.
 Multiple IP Addresses
The virtual device can manage multiple IP addresses, including
secondary IP addresses. Therefore, if you have multiple subnets
configured on an Ethernet interface, you can configure VRRP on each
subnet
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8. GLBP:
Gateway Load Balancing Protocol (GLBP) is a Cisco
proprietary protocol that attempts to overcome the limitations of
existing redundant router protocols by adding basic load balancing
functionality. In addition to being able to set priorities on different
gateway routers, GLBP allows a weighting parameter to be set.
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9. Benefits of GBLP:-
 Load Sharing
You can configure GLBP in such a way that traffic from LAN clients can be shared
by multiple routers, thereby sharing the traffic load more equitably among available routers.
 Multiple Virtual Routers
GLBP supports up to 1024 virtual routers (GLBP groups) on each physical interface
of a router, and up to 4 virtual forwarders per group.
 Preemption
The redundancy scheme of GLBP enables you to preempt an active virtual gateway
with a higher priority backup virtual gateway that has become available. Forwarder preemption
works in a similar way, except that forwarder preemption uses weighting instead of priority and
is enabled by default.
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10. HSRP:
Hot Standby Router Protocol (HSRP) is a
Cisco proprietary redundancy protocol for
establishing a fault-tolerant default gateway.
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11. HSRP:
 Cisco Proprteray
 1 Active & 1 Standby router & 1 or more listening routers
 Use virtual ip add as gateway
 Hello 3 sec & hold-down timer 10 sec
 We can enable preempt manually(standby 1 preempt)
 Multicast at : 224.0.0.2(ver 1), Multicast at :224.0.0.102(ver2). Both
versions are use udp port 1985
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12. HSRP States
HSRP consists of 5 states:
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State Description
Initial This is the beginning state. It indicates HSRP is not running. It happens when the
configuration changes or the interface is first turned on
Listen The router knows both IP and MAC address of the virtual router but it is not the active or
standby router. For example, if there are 3 routers in HSRP group, the router which is not
in active or standby state will remain in listen state.
Speak The router sends periodic HSRP hellos and participates in the election of the active or
standby router.
Standby In this state, the router monitors hellos from the active router and it will take the active
state when the current active router fails (no packets heard from active router)
Active The router forwards packets that are sent to the HSRP group. The router also sends
periodic hello messages

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Protocol
Features
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
Optimization features
Tracking yes yes yes
Preempt yes yes yes
Timer
adjustments
yes yes yes

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