Inter-area summarization of edge-device addresses using RFC3107

• US 20070258447A1
• Filed: 05/04/2006
• Published: 11/08/2007
• Est. Priority Date: 05/04/2006
• Status: Abandoned Application

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Raszuk, Robert, Guichard, James
• Application Number:
  US11/417,703
• Publication Number:
  US 20070258447A1
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]

Abstract

A method, apparatus and computer program product for performing inter-area summarization for edge-device addressing are presented. A network is established, the network including a first ABR, an ingress Provider Edge (PE) device in communication with the first ABR, a second ABR in communication with the first ABR, and an egress PE in communication with the second ABR. The first ABR and the second ABR are connected via an RFC3107 BGP session, as are the ingress PE and the first ABR as well as the egress PE and second ABR. The method further includes performing packet forwarding including PE address summarization through the network.

Claims

1. A method of performing inter-area summarization for edge-device addressing, the method comprising:

establishing a network comprising a first ABR, an ingress Provider Edge (PE) device in communication with said first ABR, a second ABR in communication with said first ABR, an egress PE in communication with said second ABR, wherein said first ABR and said second ABR are connected via an RFC3107 BGP session, wherein said ingress PE and said first ABR are connected via an RFC3107 BGP session;

wherein said egress PE is connected to said second ABR via an RFC3107 BGP session; and

performing packet forwarding including PE address summarization through said network.

2. The method of claim 1 wherein said establishing a network further comprises:

said second ABR redistributing /32routes from an area associated with said second ABR and said egress PE into BGP; and

enabling RFC 3107 mode for said routes such that a next-hop for said routes includes said second ABR.

3. The method of claim 2 further comprising;

said first ABR receiving an RFC3107 update from said second ABR, said update including all the /32addresses from said area associated with said second ABR and said egress PE;

said first ABR performing next-hop-self, triggering new RFC3107 label assignments; and

propagating said label assignments to said ingress PE.

4. The method of claim 3 further comprising:

said ingress PE installing BGP VPN route containing next hop address of said egress PE, resolving said first egress PE next hop via 3107 route with label associated to first ABR which are resolved via IGP &

LDP label;

said ingress PE recursing a route via a local area IGP and applying a label for forwarding to said first ABR; and

said ingress PE matching VPNv4 routes containing PEs next-hops with routes received via RFC3107 and local IGP routes to populate an LFIB of said ingress PE with a frame stack including a LDP label to reach said first ABR, a label for said second ABR RFC3107 label for a remote PE and a VPN label.

5. The method of claim 4 wherein said performing packet forwarding including PE address summarization through said network comprises:

said first ABR receiving a packet with a frame stack of the label for said second ABR and a VPN label;

said first ABR replacing the label for the second ABR with a RFC3107 label received from said second ABR; and

pushing an IGP area label to reach said second ABR onto said frame stack.

6. The method of claim 5 further comprising:

said second ABR receiving the packet from said first ABR;

replacing the RFC3107 label received from said second ABR with the appropriate /32label of the destination PE; and

forwarding said packet to the destination PE.

7. A computer readable medium having computer readable code thereon for of performing inter-area summarization for edge-device addressing, the medium comprising:

instructions for establishing a network comprising a first ABR, an ingress Provider Edge (PE) device in communication with said first ABR, a second ABR in communication with said first ABR, an egress PE in communication with said second ABR, wherein said first ABR and said second ABR are connected via an RFC3107 BGP session, wherein said ingress PE and said first ABR are connected via an RFC3107 BGP session;

wherein said egress PE is connected to said second ABR via an RFC3107 BGP session; and

instructions for performing packet forwarding including PE address summarization through said network.

8. The computer readable medium of claim 7 wherein said instructions for establishing a network further comprises:

instructions for said second ABR redistributing /32routes from an area associated with said second ABR and said egress PE into BGP; and

instructions for enabling RFC 3107 mode for said routes such that a next-hop for said routes includes said second ABR.

9. The computer readable medium of claim 8 further comprising;

instructions for said first ABR receiving an RFC3107 update from said second ABR, said update including all the /32addresses from said area associated with said second ABR and said egress PE;

instructions for said first ABR performing next-hop-self, triggering new RFC3107 label assignments; and

instructions for propagating said label assignments to said ingress PE.

10. The computer readable medium of claim 9 further comprising:

instructions for said ingress PE installing BGP VPN route containing next hop address of said egress PE, resolving said first egress PE next hop via 3107 route with label associated to first ABR which are resolved via IGP &

LDP label;

instructions for said ingress PE recursing a route via a local area IGP and applying a label for forwarding to said first ABR; and

instructions for said ingress PE matching VPNv4 routes containing PEs next-hops with routes received via RFC3107 and local IGP routes to populate an LFIB of said ingress PE with a frame stack including a LDP label to reach said first ABR, a label for said second ABR RFC3107 label for a remote PE and a VPN label.

11. The computer readable medium of claim 10 wherein said instructions for performing packet forwarding including PE address summarization through said network comprises:

instructions for said first ABR receiving a packet with a frame stack of the label for said second ABR and a VPN label;

instructions for said first ABR replacing the label for the second ABR with a RFC3107 label received from said second ABR; and

instructions for pushing an IGP area label to reach said second ABR onto said frame stack.

12. The computer readable medium of claim 11 further comprising:

instructions for said second ABR receiving the packet from said first ABR;

instructions for replacing the RFC3107 label received from said second ABR with the appropriate /32label of the destination PE; and

instructions for forwarding said packet to the destination PE.

13. A network device performing as a ingress Provider Edge (PE) router, comprising:

a memory;

a processor;

a communications interface;

an interconnection mechanism coupling the memory, the processor and the communications interface; and

wherein the memory is encoded with an inter-area summarization for edge-device addressing application that when performed on the processor, provides a process for processing information, the process causing the computer system to be capable of performing the operations of;

establishing a network between an ingress Provider Edge (PE) device and a first ABR, wherein said ingress PE and said first ABR are connected via an RFC3107 BGP session; and

performing packet forwarding including PE address summarization through said network.

14. The network device of claim 13 wherein said ingress PE installs BGP VPN route containing next hop address of an egress PE, resolves said first egress PE next hop via 3107 route with label associated to a first ABR which are resolved via IGP &

LDP label;

said ingress PE recurses a route via a local area IGP and applying a label for forwarding to said first ABR; and

said ingress PE matches VPNv4 routes containing PEs next-hops with routes received via RFC3107 and local IGP routes to populate an LFIB of said ingress PE with a frame stack including a LDP label to reach said first ABR, a label for said second ABR RFC3107 label for a remote PE and a VPN label.

15. A network device performing as a first ABR, comprising:

a memory;

a processor;

a communications interface;

an interconnection mechanism coupling the memory, the processor and the communications interface; and

wherein the memory is encoded with an inter-area summarization for edge-device addressing application that when performed on the processor, provides a process for processing information, the process causing the computer system to be capable of performing the operations of;

establishing a network comprising the first ABR, an ingress Provider Edge (PE) device in communication with said first ABR, a second ABR in communication with said first ABR, wherein said first ABR and said second ABR are connected via an RFC3107 BGP session, wherein said ingress PE and said first ABR are connected via an RFC3107 BGP session; and

performing packet forwarding including PE address summarization through said network.

16. The network device of claim 15 wherein said first ABR receives an RFC3107 update from said second ABR, said update including all the /32addresses from said area associated with said second ABR and said egress PE;

said first ABR performs next-hop-self, triggering new RFC3107 label assignments; and

said first ABR propagates said label assignments to said ingress PE.

17. The network device of claim 16 wherein said first ABR receives an RFC3107 update from a second ABR, said update including all the /32addresses from an area associated with said second ABR and said egress PE;

said first ABR performs next-hop-self, triggering new RFC3107 label assignments; and

said first ABR propagates said label assignments to said ingress PE.

18. A network device performing as a second ABR, comprising:

a memory;

a processor;

a communications interface;

an interconnection mechanism coupling the memory, the processor and the communications interface; and

wherein the memory is encoded with an inter-area summarization for edge-device addressing application that when performed on the processor, provides a process for processing information, the process causing the computer system to be capable of performing the operations of;

establishing a network comprising the second ABR in communication with a first ABR, an egress PE in communication with said second ABR, wherein said first ABR and said second ABR are connected via an RFC3107 BGP session, wherein said egress PE is connected to said second ABR via an RFC3107 BGP session; and

performing packet forwarding including PE address summarization through said network.

19. The network device of claim 18 wherein said second ABR redistributes /32routes from an area associated with said second ABR and said egress PE into BGP;

and

enables RFC3107 mode for said routes such that a next-hop for said routes includes said second ABR.

20. The network device of claim 19 wherein said second ABR receives a packet from said first ABR;

replaces the RFC 3107 label received from said second ABR with the appropriate /32label of a destination PE; and

forwards said packet to the destination PE.

22. The system of claim 20 wherein said ingress PE installs BGP VPN route containing next hop address of an egress PE, resolves said first egress PE next hop via 3107 route with label associated to a first ABR which are resolved via IGP &

LDP label;

said ingress PE recurses a route via a local area IGP and applying a label for forwarding to said first ABR; and

said ingress PE matches VPNv4 routes containing PEs next-hops with routes received via RFC3107 and local IGP routes to populate an LFIB of said ingress PE with a frame stack including a LDP label to reach said first ABR, a label for said second ABR RFC3107 label for a remote PE and a VPN label.

23. The system of claim 20 wherein said first ABR receives an RFC3107 update from said second ABR, said update including all the /32addresses from said area associated with said second ABR and said egress PE;

said first ABR performs next-hop-self, triggering new RFC3107 label assignments;

said first ABR propagates said label assignments to said ingress PE;

said first ABR receives an RFC3107 update from a second ABR, said update including all the /32addresses from an area associated with said second ABR and said egress PE;

said first ABR performs next-hop-self, triggering new RFC3107 label assignments; and

said first ABR propagates said label assignments to said ingress PE.

24. The network device of claim 20 wherein said second ABR redistributes /32routes from an area associated with said second ABR and said egress PE into BGP;

enables RFC 3107 mode for said routes such that a next-hop for said routes includes said second ABR;

receives a packet from said first ABR;

replaces the RFC3107 label received from said second ABR with the appropriate /32label of a destination PE; and

forwards said packet to the destination PE.

21. A communications system capable performing inter-area summarization for edge-device addressing, the system comprising:

a first ABR;

an ingress Provider Edge (PE) device in communication with said first ABR, wherein said ingress PE and said first ABR are connected via an RFC3107 BGP session;

a second ABR in communication with said first ABR, wherein said first ABR and said second ABR are connected via an RFC3107 BGP session; and

an egress PE in communication with said second ABR, wherein said egress PE is connected to said second ABR via an RFC3107 BGP session; and

wherein said ingress PE, said first ABR, said second ABR and said egress PE are connected by way of a network and wherein said system performs packet forwarding including PE address summarization through said network.