Welcome to the Computer Science and Technology Study Materials section from CoreNetworkZ EdTech Solutions, a leading mock test and competitive exam preparation platform, for students preparing for SSC, DSSSB, and Kerala PSC examinations. Today, I will explain Virtual Router Redundancy Protocol (VRRP).
Virtual Router Redundancy Protocol (VRRP) is an open protocol (not a proprietary protocol). It introduces the concept of the virtual router to improve the redundancy of the default gateway of hosts.
This article checks the uses and importance of VRRP.
How does This Study Material help PSC, SSC, and DSSSB Aspirants?
SSC, DSSSB, and Kerala PSC conduct examinations for various IT posts.
Understanding Virtual Router Redundancy Protocol (VRRP) is essential for candidates appearing for the Kerala PSC Degree Level Exam, SSC Scientific Assistant (CS), and System Analyst posts. These networking fundamentals are core parts of the Computer Science syllabus.
Kerala PSC Degree Level examinations have a Computer Science section where students can expect questions from Network Protocols. You can check the Kerala PSC Degree Level Common Prelims Syllabus under the Computer Science section. I recommend you download the syllabus using this official link.
Reference: https://www.keralapsc.gov.in/sites/default/files/2021-02/syllubus.pdf
How Does VRRP Assure Network Redundancy?
One commenter, Frank, asked about how VRRP ensures the Network Redundancy. Another reader, Kevin Thomas, asked about using a virtual router in this protocol. Let me answer both here.
According to VRRP, a virtual router (VR) is not just a physical router but includes the master and backup routers.
So, the default gateway of a host is the VR instead of a single physical router.
This VR concept ensures that if one router fails, another will take the charge immediately. However, at a time, only one master acts as the default gateway, and the master informs the backup routers of its current status.
The backup router will take place in the position of the master if the master becomes unavailable.
Can I Use VRRP with HSRP?
Ronald asked me if he could configure a Cisco router with VRRP. Cisco uses a different protocol, HSRP.
Virtual Router Redundancy Protocol is an open-source protocol similar to Cisco's proprietary protocol, the Hot Standby Router Protocol (HSRP). However, both protocols are not compatible despite their similarities.
We cannot use VRRP with HSRP.
You have learned the basics of VRRP. Let us check how to configure the Virtual Router Redundancy Protocol.
VRRP Configurations Tips
Kanaka Raj, a young network engineer, wanted a tutorial on configuring VRRP. I guess the steps below will help him learn it.
The Virtual Router (VR) works as the default gateway of hosts.
A group of physical routers comes under VR, but only one master at a time.
The master router informs backup routers of its current status (all the time).
When the master fails, one backup router assumes the role of master.
The concept of VirtualRuter by Virtual Router Redundancy Protocol improves network redundancy.
The MAC address of the VR must be in this format: 00-00-5E-00-01-XX.
The IP address used for multicast is 224.0.0.18.
You have learned the basics of the Virtual Router Redundancy Protocol and its application in a network.
Study Notes: High Availability & Gateway Redundancy (VRRP)- This topic is a key part of the Computer Networks syllabus for the Kerala PSC Degree Level Exams, SSC Scientific Assistant (Computer Science), and DSSSB PGT/TGT Computer Science. Expect questions on protocol standards, Master/Backup roles, and Virtual IP logic.
Reference
You have learned the basics of VRRP. For further studies, I recommend the following tutorials from Cisco and Juniper.
- https://www.juniper.net/documentation/us/en/software/junos/high-availability/topics/topic-map/vrrp-understanding.html
- https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipapp_fhrp/configuration/15-mt/fhp-15-mt-book/fhp-vrrp.html
- https://www.cisco.com/c/en/us/td/docs/routers/crs/software/crs_r4-0/addr_serv/configuration/guide/ic40crs1book_chapter10.html

Hi Alex,
ReplyDeleteWhat is the use of a virtual router in the VRRP?
Hello Kevin,
DeleteI have explained the uses of the virtual router concept in the tutorial.
I am new to this networking career. Can you explain the basic configuration of VRRP?
ReplyDeleteSure, Kanaka Raj. I have written a seven steps process to configure the VRRP. I suggest you read it.
DeleteIt is a good tutorial, Alex. Let me ask you if I can configure VRRP on a Cisco router.
ReplyDeleteYes, Ronald, you can. However, if you use HSRP on the Cisco router, VRRP won't work with it.
DeleteHello Alex George,
ReplyDeleteHow is the Virtual MAC Address generated? It sounds a bit complicated.
Hello Mads,
DeleteThere is no complication. VRRP generates the Virtual MAC Address automatically. It takes the last eight bits of the hexadecimal VRRP group number.
Hi Alex,
ReplyDeleteCan VRRP really assure the total redundancy? If yes, how?
Yes Frank, it does. I have explained that part in the tutorial.
Delete