- Basically we use a single gateway to reach the Internet. But what will happen, if this gateway will go down or something will wrong in that gateway. In this situation we will be completely isolated from internet. Because there is no redundancy of gateway.
- Check the below scenario, this scenario has a single gateway SWITCH-1, so if SWITCH-1 will go down or something will wrong in SWITCH-1 then HOST-1 will be completely isolated from internet.
- So this type lack of redundancy may be unacceptable in business or in production which required maximum up time.
- So, to overcome this issue (single point of failure) and to provide redundancy on gateway, Cisco devices support these three protocols that provide redundancy by creating a virtual gateway :
VRRP (Virtual Router Redundancy Protocol)
GLBP (Gateway Load Balancing Protocol)
Check the below topology for better understanding about Gateway redundancy -
Check the below topology for better understanding about Gateway redundancy -
- There is one host connected to a switch. And two multi-layer switches (SWITCH-1 and SWITCH-2), both have an IP address which will be used as the default gateway for the host(HOST-1).
- There are two gateway SWITCH-1 and SWITCH-2, you can configure only one gateway on HOST-1.
- Suppose we are using SWITCH-1 as a gateway for HOST-1, and SWITCH-1 went down. Then HOST-1 will be isolated.
- Now we will create virtual gateway to overcome this issue.
- We will create a virtual gateway between SWITCH-1 and SWITCH-2, and this virtual gateway has its own IP address 192.167.10.3.
- So now HOST-1 will use 192.167.10.3 as its default gateway. And one switch will be working as Active gateway, if Active gateway went down or fail then other one will take over. This the Gateway Redundancy
We will learn about HSRP, VRRP and GLBP in next post :-
Hello and welcome to networktopic Blog. My name is Anubhav. I am a Senior Network Egineer. I have created this blog specially to serve interview questions and answer on Network Routing and Switching, I will try my best to serve correct and updated networking knowledge for you as per my corporate experience.
0 comments:
Post a Comment
If you like my posts then please comment and if you don’t like then please suggest me to improve, and if you have any query related to post then please text me through the comment box or mail me on upadhyayambition@gmail.com , I will try my best to solve your queries as soon as possible.