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Virtual Router Redundancy Protocol – TechAcad.net

The Virtual Router Redundancy Protocol (VRRP) is an election protocol that dynamically assigns responsibility for one or more virtual routers to the...

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virtual-router-redundancy-protocol

The Virtual Router Redundancy Protocol (VRRP) is an election protocol that dynamically assigns responsibility for one or more virtual routers to the VRRP routers on a LAN, allowing several routers on a multiaccess link to utilize the same virtual IP address.

A VRRP router is configured to run the VRRP protocol in conjunction with one or more other routers attached to a LAN. In a VRRP configuration, one router is elected as the virtual router master, with the other routers acting as backups in case the virtual router master fails.

 

HSRP

VRRP

Proprietary

Cisco proprietary

IETF – RFC 3768

Number of groups

16 groups maximum

255 groups maximum

Active/Standby

1 active, 1 standby and multiple candidates.

1 active and several backups.

Virtual IP Address

Different from real IP addresses on interfaces

Can be the same as the real IP address on an interface.

Multicast address

224.0.0.2

224.0.0.18

Tracking

Interfaces or Objects

Objects

Timers

Hello timer 3 seconds, hold time 10 seconds.

Hello timer 1 second, hold time 3 seconds.

Authentication

Supported

Not supported in RFC 3768

Virtual router redundancy protocol

Configuring VRRP

SW1 and SW2 are multilayer switches and their interfaces are configured as routed ports. We will create a virtual gateway using VRRP on the interfaces facing Switch0:

Here’s an example how to configure VRRP. You can see the commands are pretty much the same but I didn’t type “standby” but vrrp. I have changed the priority on SW1 to 150 and I’ve enabled MD5 authentication on both switches.

SW1(config)#interface g1/0/1
SW1(config-if)#vrrp 1 ip 192.168.1.1
SW1(config-if)#vrrp 1 priority 150
SW1(config-if)#vrrp 1 authentication md5 key-string techacad

SW2(config-if)#interface g1/0/1
SW2(config-if)#vrrp 1 ip 192.168.1.1
SW2(config-if)#vrrp 1 authentication md5 key-string techacad

Use show vrrp to verify your configuration. The output looks similar to HSRP but one of the
differences is that VRRP uses another virtual MAC address:

0000.2a00.01XX (where X = group number)

You can also use load balancing with VRRP by creating two VRRP groups and making SW1 primary for one group and secondary in other VRRP group. In this way you will need to create two virtual gateways or virtual IPs for each VRRP group. However, this load balacing does not work like per packet load balancing but you can use this scenario on per VLAN basis.

That’s it for now on Virtual Router Redundancy Protocol, i hope this has been informative for you and i would like to thank you for viewing.

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