How to create redundancy in network

Posted on 2009-02-10
Last Modified: 2012-05-06

We have one ISP , one router and one Firewall .
We are going to buy another ISP , Router , Firewall .
Can somebody tell how to create a redundancy

1.One ISP fails internet should go thru the other ,
2.One router fails the other will take over
3..One Firewall fails other will take over

Can some body give me some links or explain the network arc in brief so that I can work on it.
Question by:megavannan
    LVL 5

    Accepted Solution

    For redundancy of ISP's you will have to configure BGP on the routers.
    For redundancy of devices you can configure HSRP.



    Good Luck! :)
    LVL 2

    Assisted Solution

    BGP is a rather complex topic and the above link provides all you need to know....but maybe a bit more for your project. I think this link may be more specific to your project:

    I am attaching a sketch for what you would want to work towards implementing.  I didn't include the physical layer redundancy, but you'd want to include redundant switches for your connections, with etherchannel trunks, lan-based failover for your firewalls (if you need a sketch of that, let me know).
    Are you getting ethernet circuits from your ISPs or traditional serial circuits (DS3, etc...)... having MetroE circuits will require some additional configuration (ie. Object tracking) for the "HSRP" to work properly.

    When you're ready for the actual configuration, you have to make absolutely certain that your BGP is configured properly, or you run the risk of being a transit between your two ISPs...  when you're ready to cross that road, if you need more help, do post again.

    Hope this helps

    LVL 2

    Expert Comment

    Hi Mega: are all set with this or do you need further assistance?

    Author Comment

    Hi Ciscoml320

    I am sorry for asking you this query after a long time...
    But can you pls tell me in your proposed diagram

    1..If I can load balance between (using route maps) the two ISP
    2..Will any link failure , apart from device failure also not cause any disruptions..
    3.. I have cisco L3 switches as well , how do i use it in your diagram.

    Pls reply and thanks in advance


    Author Comment

    The two L3 switches are stacked using stacking cable , Also Please detail me the configuration between firewall and router also

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