Method and apparatus to enable an IPe domain through EIGRP

• US 7,940,668 B2
• Filed: 03/21/2008
• Issued: 05/10/2011
• Est. Priority Date: 03/21/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Retana, Alvaro E., Yang, Yi, White, Russell I.
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): Yuen; Kan
• Application Number:
  US12/052,861
• Publication Number:
  US 20090238076A1
• Time in Patent Office: 1,145 Days
• Field of Search: 370/238, 370/252, 370/253, 370/389, 370392-39531
• US Class Current: 370/238
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/025 Updating only a limited number of routers, e.g. fish-eye update
• CPC Class Codes: H04L 45/033 by updating distance vector protocols
• CPC Class Codes: H04L 45/12 Shortest path evaluation

Abstract

In one embodiment, a system, method, and apparatus for preventing excessive transmission of routing information in a communications network occurs by receiving a network routing address at a connection node in a communications network, the network routing address allowing the transmission of data packets from a source node to a destination node in the communications network; determining a longest summary route covering a path to the destination node; creating a list comprising a summary of all neighbor connection nodes of the connection node; and transmitting an update of the longest summary route of the network routing address towards all neighbor nodes advertising a destination address comprising a shorter address prefix, wherein the transmitting process occurs sequentially beginning with a first neighbor connection node entered in the list.

Claims

1. A method comprising:

receiving, at a connection node in a communications network, a network routing address for transmitting data packets from a source node to a destination node;

comparing a cost of selecting said network routing address with costs of preexisting entries of network routing addresses in a routing table stored at said connection node;

selecting neighbor connection nodes with the network routing address associated with the lowest cost;

determining which selected neighbor connection nodes send a summary route to the destination node having a longest destination address prefix, which is included in a different routing table, and which covers a path to said destination node;

transmitting the summary route having the longest destination address prefix to a plurality of neighbor connection nodes of the connection node configured for advertising a shorter prefix to reach said destination node;

creating a list comprising a summary of all neighbor connection nodes of said connection node;

selecting a first neighbor connection node from said list;

determining whether a summary route exists from said first neighbor connection node to said destination node; and

removing said first neighbor connection node from said list.

2. The method of claim 1, wherein said connection node comprises a router.

3. The method of claim 1, wherein said communications network comprises an Internet Protocol Everywhere (IPe) network running a Distance-Vector (DV) protocol.

4. The method of claim 3, wherein said DV protocol comprises an Enhanced Interior Gateway Routing Protocol (EIGRP).

5. The method of claim 1, further comprising transmitting said summary route to said first neighbor connection node prior to the removal of said first neighbor connection node from said list.

6. The method of claim 1, wherein if no selected neighbor connection nodes exist, then said method comprising sending an update of the summary route of the network routing address to the neighbor connection nodes.

7. The method of claim 1, wherein said cost comprises a network line cost associated with delay, bandwidth, reliability, traffic, and latency for said data packets to be transmitted in said communications network.

8. An apparatus comprising:

means for receiving a network routing address at a connection node in a communications network, the network routing address allowing the transmission of data packets from a source node to a destination node in said communications network;

means for comparing a cost of selecting said network routing address with costs of preexisting entries of network routing addresses in a routing table stored at said connection node;

means for selecting neighbor connection nodes with the routing address associated with the lowest cost;

means for determining which selected neighbor connection nodes send a summary route, which is included in a different routing table, and which covers a path to said destination node, wherein the summary route reflects a path to the destination node having a longest destination address prefix;

means for creating a list comprising a summary of all neighbor connection nodes of said connection node;

means for selecting a first neighbor connection node from said list;

means for determining whether a summary route exists from said first neighbor connection node to said destination node;

removing said first neighbor connection node from said list; and

means for transmitting the summary route having the longest destination address prefix to the plurality of neighbor connection nodes of the connection node configured for advertising a shorter prefix to reach said destination node.

9. The apparatus of claim 8, wherein said connection node comprises a routing device.

10. The apparatus of claim 8, wherein said communications network comprises an Internet Protocol Everywhere (IPe) network running a Distance-Vector (DV) protocol.

11. The apparatus of claim 10, wherein said DV protocol comprises an Enhanced Interior Gateway Routing Protocol (EIGRP).

12. The apparatus of claim 8, further comprising means for removing said neighbor connection nodes from said list after said transmitting process.

13. The apparatus of claim 8, further comprising means for sending an update of the summary route of the network routing address to the neighbor connection nodes, if no selected neighbor connection nodes exist.

14. An apparatus comprising:

a connection node located in a communications network and configured to receive a network routing address for transmitting data packets from a source node to a destination node in said communications network;

a routing table stored at said connection node configured to compare a cost of selecting said network routing address with costs of preexisting entries of network routing addresses in said routing table;

a processor operatively connected to said connection node, wherein said processor is configured to;

select neighbor connection nodes with the network routing address comprising the lowest cost;

determine which selected neighbor connection nodes send a summary route to the destination node having a longest destination address prefix, which is included in a different routing table, and which covers a path to said destination node, and

sending the summary route having the longest destination address prefix to a plurality of neighbor connection nodes of the connection node configured for advertising a shorter prefix to reach said destination node, wherein a list stored at said connection node comprises a summary of the neighbor connection nodes of said connection node, wherein said processor is configured to select a first neighbor connection node from said list, to determine whether a summary route exists from said first neighbor connection node to said destination node, and to remove said first neighbor connection node from said list.

15. The apparatus of claim 14, wherein said connection node comprises a routing device.

16. The apparatus of claim 14, wherein said communications network comprises an Internet Protocol Everywhere (IPe) network running a Distance-Vector (DV) protocol.

17. The apparatus of claim 16, wherein said DV protocol comprises an Enhanced Interior Gateway Routing Protocol (EIGRP).

18. The apparatus of claim 14, wherein said processor is adapted to transmit said summary route to said first neighbor connection node prior to the removal of said first neighbor connection node from said list.

19. The apparatus of claim 14, wherein said cost comprises a network line cost associated with delay, bandwidth, reliability, traffic, and latency for said data packets to be transmitted in said communications network.