Redudancy and Load balancing In Network

In real time scenario every organization wants redundancy  and Load balancing. So today I am going to write on this topic.

First question arise in our mind what is  Redundancy and Load Balancing and why we need it.

With the help of Redundancy  we can create backup connection. For eg. in my organization I have a BSNL connection and for Backup I have Airtel Connection.  Because I have to support my client 24*7 and I can't believe on a  single ISP. So I have a backup connection. But what if I have lost a connection and doing some serious work. Should I run to another router to create connection, not a good idea because I take time to create a physical connection.

Another one is I have connected with both router at a time but now problem is that we have to give a default gate way in our PC when using Internet so which address should I give. And when this Default Gateway goes down I have to change my PC settings.

So finally we want a connection where we can connect both router  at a time and when I when one router goes down my backup router work automatically.

And with this process we can create Redundancy in our Network.


Now question arise that what is LOAD BALANCING. We are using both router and we have to pay to both ISP. Whether  we are using it or not. So I have one more idea can I use both router at a time and when my one router goes down another will take all load. Ya it's good idea I think.



So we have 3 protocol which are used for Redundancy  and Load Balancing.
1.HSRP (Hot Standby Router Protocol)
2.VRRP (Virtual Router Redundancy Protocol)
3.GLBP (Gateway Load Balancing Protocol)

Both 1 and 2 are use only for Redundancy and 3 rd one is used for both Redundancy and Load Balancing.

I'll write about them also...

Thanks for Reading... ---Himanshu Saxena