MPLS Network Mesh Topology : DC-DR Setup

Pain Area and aspects for consideration:

• If MPLS circuit goes down at DC location?
• Will it be a manual intervention?  
• Should customer takes 2 different MPLS Service provider at DC-DR location for redundancy?
• Will it be a cost effective solution?
• Why required another Point to point connectivity between DC-DR?
• What would be the best topology in DC-DR scenario?
• What Routing protocol needs to be run between CE-PE?

Solution Proposed :

In MPLS VPN this is one of the most widely deployed scenarios by the organizations – MPLS network with DC-DR setup either on Dual Hub and Spoke or Mesh Topology. If DC location goes down in that case DR would become DC for all the corresponding users and application is seamlessly accessible without any delay or interference. Most of the organizations deploy mission critical applications like-ERP, Mailing, CRM, POS into their Intranet which they wanted to be access by the users all the time, so IT team create parallel set up of all the critical applications to another location which become DR site. Customers has to take Point to point connectivity from service provider between DC-DR for data synchronization because in ideal scenario users would always access applications from DC location and whenever DC goes down DR would become active and should always have latest/updated data for users. There are so many different ways to achieve this scenario – 1^st Customer have to allocate 2 different IP’s to their DNS entry for the hosted application which will work as Active-Failover Scenario in MPLS network.2^nd Customer allocate same subnet for DC-DR but never plug DR location into live network until and unless DC down.3^rd is configure same LAN IP Pool in DC and DR with setting priority to DC Subnet through BGP. Return Traffic will manipulate not Forward Traffic.

Technical Arrangement:

1. Topology Support – Dual Hub and Spoke or MESH Topology.
2. Recommended eBGP routing protocol in between CE-PE.
3. Configure same LAN IP pool in DC and DR location.
4. Configure eBGP with As path prepend attribute for setting priority to DC LAN IP Pool.
5. Configure Routers LAN Interface as a default gateway IP address of all the users.
6. For forward traffic active server will always respond to spokes queries.
7. Routers should have minimum 1 Layer 3 port + 1 Layer 2 port.
8. Routers should support all the BGP as Routing protocol.