Method and apparatus for exchanging routing information and the establishment of connectivity across multiple network areas
View Patent ↗Routes may be installed across multiple link state protocol controlled Ethernet network areas by causing ABBs to leak I-SID information advertised by BEBs in a L1 network area into an L2 network area. ABBs will only leak I-SIDs for BEBs where it is the closest ABB for that BEB. Where another ABB on the L2 network also leaks the same I-SID into the L2 network area from another L1 network area, the I-SID is of multi-area interest. ABBs will advertise I-SIDs that are common to the L1 and L2 networks back into their respective L1 network. Within each L1 and L2 network area, forwarding state will be installed between network elements advertising common interest in an ISID, so that multi-area paths may be created to span the L1/L2/L1 network areas. The L1/L2/L1 network structure may recurse an arbitrary number of times.
1. A method of installing connectivity across first and second network areas interconnected by at least a first Area Boundary Bridge (ABB), the first network area being a link state protocol controlled Ethernet network comprising a first plurality of network elements implementing a first control plane, the first plurality of network elements comprising a first set of Backbone Edge Bridges (BEBs), the method comprising:
receiving, at the first ABB from a first set of BEBs, first community of interest identifiers;
leaking the first community of interest identifiers by the first ABB from the first network area into the second network area;
listening, by the first ABB, for second community of interest identifiers leaked by other ABBs into the second network area;
comparing the first community of interest identifiers to the second community of interest identifiers to identify matching community of interest identifiers in the first and second network areas, the matching community of interest identifiers including community of interest identifiers that are common to the first and second network areas; and
advertising, by the first ABB into the first network area, the matching community of interest identifiers.
2. The method of claim 1 , wherein the community of interest identifiers are Ethernet I-component service identifiers (I-SIDs).
3. The method of claim 2 , wherein leaking the first community of interest identifiers by the first ABB from the first network area into the second network area comprises transmitting a link state advertisement containing a destination media access control (MAC) address and the community of interest identifiers into the second network area.
4. The method of claim 3 , wherein the destination MAC address is a MAC address of one of the BEBs in the first network area.
5. The method of claim 3 , wherein the destination MAC address is a MAC address of the first ABB.
6. The method of claim 1 , further comprising representing, by the first ABB into the second network area, a subset of the BEBs in the first network area, wherein leaking the first community of interest identifiers by the first ABB from the first network area into the second network area comprises leaking only community of interest identifiers received from the subset of BEBs represented by the first ABB.
7. The method of claim 1 , wherein the first set of BEBs are associated with the first network area, and the first community of interest identifiers are received at the first ABB from the first network area.
8. A method of installing connectivity across first and second network areas interconnected by at least a first Area Boundary Bridge (ABB), the first network area being a link state protocol controlled Ethernet network comprising a first plurality of network elements implementing a first control plane, the first plurality of network elements comprising a first set of Backbone Edge Bridges (BEBs), the method comprising:
receiving, at the first ABB from a first set of BEBs, first community of interest identifiers;
representing, by the first ABB into the second network area, a subset of the BEBs in the first network area;
leaking, by the first ABB from the first network area into the second network area, only first community of interest identifiers received from the subset of BEBs represented by the first ABB;
listening, by the first ABB, for second community of interest identifiers leaked by other ABBs into the second network area;
comparing the first community of interest identifiers to the second community of interest identifiers and identifying matching community of interest identifiers in the first and second network areas, the matching community of interest identifiers including community of interest identifiers that are common to the first and second network areas; and
advertising, by the first ABB into the first network area, the matching community of interest identifiers.
9. The method of claim 8 , wherein the community of interest identifiers are Ethernet I-component service identifiers (I-SIDs).
10. The method of claim 9 , wherein leaking the first community of interest identifiers by the first ABB from the first network area into the second network area comprises transmitting a link state advertisement containing a destination media access control (MAC) address and the community of interest identifiers into the second network area.
11. The method of claim 10 , wherein the destination MAC address is a MAC address of one of the BEBs in the first network area.
12. The method of claim 10 , wherein the destination MAC address is a MAC address of the first ABB.
13. The method of claim 8 , wherein the first set of BEBs are associated with the first network area, and the first community of interest identifiers are received at the first ABB from the first network area.
14. A method of installing connectivity across first and second network areas interconnected by at least a first Area Boundary Bridge (ABB), the first network area being a link state protocol controlled Ethernet network comprising a first plurality of network elements implementing a first control plane, the first plurality of network elements comprising a first set of Backbone Edge Bridges (BEBs), the method comprising:
receiving, at the first ABB from the first set of BEBs, first community of interest identifiers;
leaking the first community of interest identifiers by the first ABB from the first network area into the second network area;
listening, by the first ABB, for second community of interest identifiers leaked by other ABBs into the second network area;
comparing the first community of interest identifiers to the second community of interest identifiers and identifying matching community of interest identifiers in the first and second network areas, the matching community of interest identifiers including community of interest identifiers that are common to the first and second network areas; and
advertising, by the first ABB into the first network area, the matching community of interest identifiers.
15. The method of claim 14 , wherein the community of interest identifiers are Ethernet I-component service identifiers (I-SIDs).
16. The method of claim 15 , wherein leaking the first community of interest identifiers by the first ABB from the first network area into the second network area comprises transmitting a link state advertisement containing a destination media access control (MAC) address and the community of interest identifiers into the second network area.
17. The method of claim 16 , wherein the destination MAC address is a MAC address of one of the BEBs in the first network area.
18. The method of claim 16 , wherein the destination MAC address is a MAC address of the first ABB.
19. The method of claim 14 , further comprising representing, by the first ABB into the second network area, a subset of the BEBs in the first network area, wherein leaking the first community of interest identifiers by the first ABB from the first network area into the second network area comprises leaking only community of interest identifiers received from the subset of BEBs represented by the first ABB.
20. The method of claim 14 , wherein the first set of BEBs are associated with the first network area, and the first community of interest identifiers are received at the first ABB from the first network area.