Customer with WARM DR site connecting to Internet - Design Guide

[mvasudevan]

I like to a post a design question and hope someone in group would be able to shed some light on this. The scenario:

Customer A has a production and a WARM DR site. There is a back-end link btw production and WARM DR site used for back-end server replication and etc.That explain why the internal LAN address cannot be same on this two sites. Next, registered IP address for the internet servers must be same, otherwise they'll have problem with domain-names. This simply means both production and warm DR site will use identical registered IP address allocated by Service provider. Under normal operating condition, all traffic routed to the production site. In the event of disaster or during monthly live testing, some of the application traffic (i.e. web, email) must be routed the DR site while maintaining other application to the production site.

How to achieve this?

Thank you,

Mohan

[wong34539]

One solution that you can consider to achieve this is to use NAT on the border routers and influence routing decisions by using BGP. Using NAT you can map multiple IP addresses on the inside network to a single inside global adddress seen by the outside network. You can advertise only the inside global addresses from both the sites to Internet so that they always use this address to reach the servers either in the Production or DR site. You can also influence the traffic flowing into each site by setting policies through BGP attibutes.