I am in the process of planning a new DC failover and have a question:
Here is the basic layout:
Bristol VSS - New failover DC - New upstream and Transit connectivity ready for reconfiguration
Edinburgh VSS - Current upstream and transit VSS
London VSS - Current corporate that connects to Edinburgh and Bristol
On the Edinburgh VSS we currently have a multitude of VLANs where their gateways are. This is accessed via multiple servers based in London VSS (absolute importance).
When I complete the change so that everything is routed to Bristol (I will stop BGP advertisements from Edinburgh to London) I cannot place the VLANs there as they already exist at Edinburgh.
Is it best to get the new transit eBGP peerings up first, then block the edinburgh iBGP advertisements to London and Bristol and then bring down the peerings at Edinburgh and advertise the routing table from Bristol?
Will the above leave the internal routing in place to the VLANs that still exist in Edinburgh VSS?
This is turning out to be a little trickier than first thought.
