Systems and methods for implementing multiple ISIS routing instances on a network element

1. A method, comprising:

instantiating a primary intermediate system to intermediate system (ISIS) instance on a network element, the network element comprising a master control unit, a switching element, and at least one network interface communicatively coupled to the switching element, the network interface comprising one or more physical ports each configured to serve as a physical interface between a transmission medium and the network interface;

instantiating a secondary ISIS instance on the network element;

associating the primary ISIS instance with a first routing partition that includes at least one first remote network element;

associating the secondary ISIS instance with a second routing partition that includes at least one second remote network element, the second routing partition being different from the first routing partition and the second remote network element being different from the first remote network element; and

configuring the primary ISIS instance and the secondary ISIS instance to appear as a single ISIS instance to other network elements remote to the network element.

2. A method according to claim 1 , further comprising configuring the primary ISIS instance and the secondary ISIS instance to appear as a single ISIS instance to Open Systems Interconnection (OSI) applications.

3. A method according to claim 2 , further comprising terminating OSI applications in the primary ISIS instance.

4. A method according to claim 3 , further comprising configuring the secondary ISIS instance to forward locally terminated traffic to the primary ISIS instance.

5. A method according to claim 1 , wherein the network element is a gateway network element.

6. A method according to claim 1 , further comprising configuring each of the primary ISIS instance and the secondary ISIS instance as a Level 1 ISIS instance.

7. A method according to claim 1 , further comprising:

configuring the primary ISIS instance and the secondary ISIS instance such that the at least one first remote network element may communicate with the at least one second network element via the network element.

8. A network element, comprising:

a master control unit;

a switching element;

at least one network interface communicatively coupled to the switching element, the network interface comprising one or more physical ports each configured to serve as a physical interface between a transmission medium and the network interface;

a primary intermediate system to intermediate system (ISIS) instance associated with a first routing partition that includes at least one first remote network element; and

a secondary ISIS instance associated with a second routing partition that includes at least one second remote network element, the second routing partition being different from the first routing partition and the second remote network element being different from the first remote network element;

wherein the primary ISIS instance and the secondary ISIS instance to appear as a single ISIS instance to other network elements remote to the network element.

9. A network element according to claim 8 , wherein the primary ISIS instance and the secondary ISIS instance are configured to appear as a single ISIS instance to Open Systems Interconnection (OSI) applications.

10. A network element according to claim 9 , wherein the primary ISIS instance is further configured such that OSI applications terminate in the primary ISIS instance.

11. A network element according to claim 10 , wherein the secondary ISIS instance is further configured to forward locally terminated traffic to the primary ISIS instance.

12. A network element according to claim 8 , wherein the network element is a gateway network element.

13. A network element according to claim 8 , wherein the first ISIS instance and the second ISIS instance are each further configured as a Level 1 ISIS instance.

14. A network element according to claim 8 , wherein:

the primary ISIS instance and the secondary ISIS instance are further configured such that the at least one first remote network element may communicate with the at least one second network element via the network element.

15. A system, comprising:

a processor; and

a non-transitory computer readable storage medium storing instructions that, when executed by the processor, cause the processor to:

instantiate a primary intermediate system to intermediate system (ISIS) instance on a network element, the network element comprising a master control unit, a switching element, and at least one network interface communicatively coupled to the switching element, the network interface comprising one or more physical ports each configured to serve as a physical interface between a transmission medium and the network interface;

instantiate a secondary ISIS instance on the network element;

associate the primary ISIS instance with a first routing partition that includes at least one first remote network element;

associate the secondary ISIS instance with a second routing partition that includes at least one second remote network element, the second routing partition being different from the first routing partition and the second remote network element being different from the first remote network element; and

configure the primary ISIS instance and the secondary ISIS instance to appear as a single ISIS instance to other network elements remote to the network element.

16. A system according to claim 15 , wherein the storage medium further stores instructions for configuring the primary ISIS instance and the secondary ISIS instance to appear as a single ISIS instance to Open Systems Interconnection (OSI) applications.

17. A system according to claim 16 , wherein the storage medium further stores instructions for terminating OSI applications in the primary ISIS instance.

18. A system according to claim 17 , wherein the storage medium further stores instructions for configuring the secondary ISIS instance to forward locally terminated traffic to the primary ISIS instance.

19. A system according to claim 15 , wherein the network element is a gateway network element.

20. A system according to claim 15 , wherein the storage medium further stores instructions for configuring each of the primary ISIS instance and the secondary ISIS instance as a Level 1 ISIS instance.

21. A system according to claim 15 , wherein the storage medium further stores instructions for configuring the primary ISIS instance and the secondary ISIS instance such that the at least one first remote network element may communicate with the at least one second network element via the network element.