Patent ID: 8837275
Filing Date: 2014-09-16
Classification: H04L

Abstract:
1. A method for routing to a first site, packets whose destination IP address is an IP address at a second site, after a failure at the second site, the first site comprising a first server, a first edge router for a first network comprising the first site, and a first Internet Service Provider (ISP) coupling the first edge router to an Internet, the second site comprising a second server, a second edge router for a second, different network comprising the second site, and a second ISP coupling the second edge router to the Internet, the first network having a unique first Autonomous System Number (ASN), the second network having a unique second ASN, said method comprising the steps of: before the failure has occurred, the first edge router configuring an announcement stating that the packets whose destination IP address is the IP address at the second site are now to be routed to the IP address at the second site via a first route disposed in the first network having the first ASN; before the failure has occurred, the second edge router periodically announcing to the second ISP a second route to the IP address at the second site, the second route being disposed in the second network having the second ASN; in response to the failure having occurred, the second edge router ceasing the periodically announcing and the first edge router using the announcement to announce to the first ISP that the first site will receive the packets whose destination IP address is the IP address at the second site via the first route in the first network having the first ASN.