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Network design of one data center with 2 ISP connection


I am working on a scenario where we have a data center (web server farm) that we are going to connect to two ISPs. We want to make sure that when one ISP fails, our web server farm is still visible from the Internet through the second ISP. When both ISPs links are up, we would like to do load-sharing between the two ISPs.

I am considering a few design options, and would like to get some feedback which one is best:

1) get public IP address from one ISP for our web farm, and advertise these IP in both ISP (but this may not work as the other ISP may not want to advertise the other ISP's IP.

2) apply for our own public IP and then have both ISP advertise it.

3) use GSS

For the above, which one would be best in terms of dynamically maintaining our web server farm visibility from the Internet in case one ISP fails

We are leaning towards using GSS, as it seems to be more flexible, and less admin work like applying for our own IP block. But I can't find much GSS config example or scenarios in our situation.

Please kindly suggest.




Re: Network design of one data center with 2 ISP connection

Hi Benny,

Are you using BGP in your network, and are you using Multi Exit Discriminator (MED ) for configuring BGP for two ISP's as it is the very common scenarion with BGP for multiple ISP then MED parameter of BGP is configured.

But I am not sure will BGP inthis scenario will help u any for load balancing for your serverfarms.

Sachin Garg

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