I have a client who's company was split in half. One half is keeping their IP ranges and ASN, and the other half must be reconfigured with a new
ASN and IP block. We have obtained the new ASN and block from ARIN and have peering agreements in place. The routers are still advertising the old ASN, and we need to make a cutover. What is the most efficient way to cut to the new IPs and ASN with the minimum amount of downtime?
I can post configs if needed.