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VRRP: Virtual Router Redundancy Protocol

Today we will talk about the another protocol named as VRRP-Virtual Router Redundancy Protocol. We already discussed about the HSRP protocol in my earlier post and it is similar kind of protocol but is open standard. 

 HSRP is a Cisco propriety protocol and cant be used on the other vendor routers like HP,Juniper, Huawei and so on. But VRRP protocol is the open standard protocol and can be used on all the routers for its functionality.

Fig 1.1- VRRP
Some of the key features of VRRP protocol as defined below:-
  • Well if we will discuss about the VRRP multicast address, VRRP uses multicast (224.0.0.18) for its hello mechanism and elections.
  • VRRP uses IP protocol number 112
  • It is defined in the IETF – RFC 3768
  • It can have maximum of 255 number of groups it means it can support upto 255 virtual routers while in HSRP it is upto 16 number of groups
  • For Active-Standby, VRRP can have 1 active and several standby routers in a VRRP group
  • The virtual IP address in VRRP can be the same real IP address on the router while it is virtual IP and is different in HSRP
  • It can track objects only in VRRP while we can track objects and interfaces in the HSRP.
  • Hello time is 1 sec and hold timer is 3 sec in VRRP while in HSRP hello time is 3 sec and hold timer is 10 sec.
  • VRRP in such a way that traffic to and from LAN clients can be shared by multiple routers, thereby sharing the traffic load more equitably among available routers. 
  • VRRP enables you to preempt a virtual router backup that has taken over for a failing virtual router master with a higher priority virtual router backup that has become available. 
  • VRRP message digest 5 (MD5) algorithm authentication protects against VRRP-spoofing software and uses the industry-standard MD5 algorithm for improved reliability and security. 

Configuration part

Master
R1(config-if)# ip address 10.0.0.1 255.255.255.0
R1(config-if)# vrrp 1 ip 10.0.0.255
R1(config-if)# vrrp 1 priority 110
R1(config-if)# vrrp 1 authentication cisco
R1(config-if)# no shut

Backup-1
R2(config-if)# ip address 10.0.0.2 255.255.255.0
R2(config-if)# vrrp 1 ip 10.0.0.255
R2(config-if)# vrrp 1 authentication cisco
R2(config-if)# no shut

Backup-2
R3(config-if)# ip address 10.0.0.3 255.255.255.0
R3(config-if)# vrrp 1 ip 10.0.0.255
R3(config-if)# vrrp 1 authentication cisco
R3(config-if)# no shut