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Roger_Rustad_16's avatar
Roger_Rustad_16
Icon for Nimbostratus rankNimbostratus
Jul 08, 2014

n00b anycast question

I have a situation where I have 3 datacenters, 2 with one provider and 1 with another provider. Each of these datacenters has its own unique BGP ASN.

 

With a GTM, how can I have one IP address serve to the closest datacenter?

 

On the GTM, I'd like to put in an a.b.c.d anycast IP address and have it serve the nearest datacenter location. Is there any upstream routing or configs by my provider necessary to make this work?

 

thanks in advance, Roger

 

BIG-IP DNS
design
ip anycast

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  • mimlo_61970's avatar
    mimlo_61970
    Icon for Cumulonimbus rankCumulonimbus
    Jul 09, 2014

    the only thing I can think of is to make sure each provider will accept the advertisement. Often times they put an exact match on the subnet size of the advertisement, and will drop anything smaller. Make sure they are setup to accept the smaller subset of your ip block that you want to use for anycast.

     

    I also believe you will need to use an entire /24 at a minimum for this. I don't think they will accept a smaller prefix. Even if they do, other routers on the internet may drop smaller advertisements, giving you mixed results.