Multi-site, multi-path to Internet - customer question - off topic ?

[Steve Benoit <sbenoit () georgianc on ca>]

Good day 

I have a question from a customer point of view.  We currently have a multi-site WAN with all our Internet connectivity 
at one site consisting of 3 ISP type connections, full BGP, including our own ASN with IPv4 and v6 addressing space.  
All up and running.

I am now looking to add Internet connectivity from a second site on our WAN for fail over in the event of a site 1 
failure.  My initial thoughts are towards another full BGP session at site 2, and perhaps something like Cisco's Global 
Site Selector, or F5's GTM to direct traffic.

I'm thinking of phasing this in over a couple of years since the "server" folks will not have full hot fail-over at 
that site for that period.  Of course, in a failure situation, the site will be expected to be live and operational 
immediately.

Any suggestions on where I should start looking ?  Any good white papers or case studies you have seen?  And 
technologies we should look at or stay away from ?

Thanks 

Steve Benoit