LISP stretched subnet mode for data center migrations

A first Locator/Identifier Separation Protocol (LISP) router at an original location, the first LISP router comprising:

• at least one memory element;
• at least one processor coupled to the at least one memory element;
• and
• a LISP routing module that when executed by the at least one processor is configured to:
• detect a first network element having a first Internet Protocol (IP) address at the original location prior to migration;
• receive, after the migration, via a mapping database from a second LISP router at a target location remote from the original location, an entry mapping the first IP address to the IP address of the second LISP router;
• wherein both the first LISP router and the second LISP router are on the same subnet, and neither the first LISP router and the second LISP router are on the data path for network elements of the original location and the target location respectively;
• and
• update a cache of the mapping database at the first LISP router to configure the first LISP router to route, to the second LISP router, traffic targeted to the first network element through the first LISP router.

A computer-readable non-transitory medium comprising one or more instructions, that when executed on a processor configure the processor to perform one or more operations comprising:

• detecting, at a second Locator/Identifier Separation Protocol (LISP) router at a target location, a first IP address of a first network element located at the target location, wherein the first network element was connected to a subnet at an original location prior to the migration using the same first IP address;
• updating, at the second LISP router, a mapping database to include an entry mapping the first IP address to the IP address of the second LISP router;
• and
• transmitting, from the second LISP router via the mapping database to the first LISP router located at the original location, the entry to update a cache of the mapping database at the first LISP router to configure the first LISP router to route traffic targeted to the first network element through the first LISP router to the second LISP router;
• wherein both the first LISP router and the second LISP router are on the same subnet, and neither the first LISP router and the second LISP router are on the data path for network elements of the original location and the target location respectively.

A second Locator/Identifier Separation Protocol (LISP) router at a target location, the second LISP router comprising:

• at least one memory element;
• at least one processor coupled to the at least one memory element;
• and
• a LISP routing module that when executed by the at least one processor is configured to:
• detect a first IP address of a first network element located at the target location, wherein the first network element was connected to a subnet at an original location prior to the migration using the same first IP address;
• update a mapping database to include an entry mapping the first IP address to the IP address of the second LISP router;
• and
• transmit via the mapping database to the first LISP router located at the original location, the entry to update a cache of the mapping database at the first LISP router to configure the first LISP router to route traffic targeted to the first network element through the first LISP router to the second LISP router;
• wherein both the first LISP router and the second LISP router are on the same subnet, and neither the first LISP router and the second LISP router are on the data path for network elements of the original location and the target location respectively.