Methods and apparatus to migrate border gateway protocol sessions between routers

A tangible machine readable medium comprising machine readable instructions which, when executed, cause a machine to perform operations comprising:

• exporting a connection state to migrate a transport control protocol connection supporting a border gateway protocol session between the first router and a session endpoint from a first router to a second router;
• after the transport control protocol connection has been migrated from the first router to the second router, emulating the session endpoint at the first router by announcing, from the first router to the second router, first routes learned by the first router from the session endpoint and obtained from a first routing information base storing routes learned by the first router, the first routing information base being different from a second routing information base storing routes for announcement by the first router, the second router to process the first routes to migrate the border gateway protocol session between the first router and the session endpoint from the first router to the second router;
• marking the first routes as exported to cause the first routes to be retained after announcing the first routes;
• and
• deleting the first routes after expiration of a first period of time during which a subsequent announcement containing the first routes has not been received by the first router.

A first router comprising:

• a memory having machine readable instructions stored thereon;
• and a processor to execute the instructions to perform operations comprising:
• exporting a connection state to migrate a transport control protocol connection supporting a border gateway protocol session between the first router and a session endpoint from the first router to a second router;
• after the transport control protocol connection has been migrated from the first router to the second router, announcing, to the second router, first routes learned from the session endpoint and contained in an exported routing information base stored at the first router, the second router to process the first routes to migrate the border gateway protocol session between the first router and the session endpoint from the first router to the second router;
• marking the first routes as exported to cause the first routes to be retained after the first routes have been announced;
• and
• deleting the first routes after expiration of a first period of time during which a subsequent announcement containing the first routes has not been received by the first router.