Methods and apparatus for automated edge device configuration in a heterogeneous network
View Patent ↗A PE device learns the address of a local CE device by monitoring the control messages, such as address resolution messages, originating from those local devices. In one embodiment, automated configuration of the PE devices participating in a Layer 2 VPN is facilitated by permitting a PE device to share the addresses for its locally-attached CE devices with the remote PE devices in the VPN. A PE device may share the addresses of the remote CE devices with the local CE devices by initiating its own control message or responding to an control message issued by one of its local CE devices. This latter mechanism in effect hides the distributed, heterogeneous nature of the network from a local CE device.
1. In a network device having memory and capable of forwarding data link layer protocols and network layer protocols, a method of transmitting packets, the method comprising:
gathering information from a control message concerning a first device in communication with a first data link;
storing the gathered information in a set of network information, the set of network information being stored in the memory;
terminating the control message at the network device;
responding to the control message using a subset of the set of network information;
providing a subset of the set of network information to a second device in communication with a second data link, the first and second data links using different data link layer protocols;
receiving, from the second device, information concerning a third device, the third device in communication with the second device through the second data link;
storing the received information in the set of network information;
providing, to the first device, network information representing the third device using a subset of the set of network information prior to receiving a request for the received information from the first device;
receiving packets from the second device; and
transmitting the packets to the first device using a subset of the set of network information.
2. The method of claim 1 wherein gathering information comprises gathering information from an address resolution message.
3. The method of claim 1 wherein gathering information comprises gathering at least one of the first device's IP address, circuit information, a VC or VPN MPLS label, or the IP address for the second device associated with that label.
4. The method of claim 1 wherein gathering information comprises gathering information concerning a first device in communication with an Ethernet data link.
5. The method of claim 4 wherein gathering information comprises gathering information from an RDP message.
6. The method of claim 1 wherein gathering information comprises gathering information concerning a first device in communication with a frame relay data link.
7. The method of claim 6 wherein gathering information comprises gathering information from an IARP message.
8. The method of claim 1 wherein gathering information comprises gathering information concerning a first device in communication with PPP data link.
9. The method of claim 8 wherein gathering information comprises gathering information from an IPCP message.
10. The method of claim 1 wherein gathering information comprises gathering information concerning a first device in communication with an ATM data link.
11. The method of claim 10 wherein gathering information comprises gathering information from an INATMARP message.
12. The method of claim 1 wherein gathering information comprises gathering information concerning a first device in communication with an HDLC data link.
13. The method of claim 1 wherein transmitting the packets comprises prepending a header identifying the second device to a received packet.
14. The method of claim 1 wherein providing the gathered information comprises transmitting an MP-BGP NLRI message to the third device.
15. The method of claim 14 wherein transmitting an MP-BGP NLRI message comprises transmitting an NLRI message including an IP address sub-TLV.
16. The method of claim 1 further comprising:
receiving additional information from the second device, the additional information concerning a fourth device; and
providing the additional information concerning the fourth device to the first device.
17. The method of claim 16 wherein providing the additional information comprises responding to the control message.
18. The method of claim 16 wherein providing the additional information comprises initiating a second control message.
19. The method of claim 1 further comprising responding to the control message using a placeholder value.
20. The method of claim 1 , wherein transmitting the packets comprises transmitting packets that originate from the third device.
21. A system that resolves network addresses between network devices on a heterogeneous network, the system comprising:
a first device having memory and capable of forwarding data link layer protocols and network layer protocols;
a second device in communication with the first device using a first data link;
a third device capable of forwarding data link layer protocols and network layer protocols; and
a fourth device in communication with the third device using a second data link, the first and second data links using different data link layer protocols;
wherein the first device gathers information concerning the second device from control messages sent by the second device, the first device is adapted to store the gathered information in a set of network information, the set of network information being stored in the memory, the first device is adapted to provide a subset of the set of network information to the third device, the first device is adapted to receive, from the third device, information concerning the fourth device, the first device is adapted to store the received information in the set of network information, the first device is adapted to provide network information representing the fourth device to the second device prior to receiving a request for the received information from the second device, the network information being based on a subset of the set of network information, the first device is adapted to transmit packets to the second device from the fourth device using a subset of the set of network information, the first device is adapted to terminate the control messages and the first device is adapted to respond to the control messages using a subset of the set of network information.
22. The system of claim 21 wherein the control messages are address resolution messages.
23. The system of claim 21 wherein the first data link is a Ethernet data link.
24. The system of claim 21 wherein the first data link is a frame relay data link.
25. The system of claim 21 wherein the first data link is a PPP data link.
26. The system of claim 21 wherein the first data link is an ATM data link.
27. The system of claim 21 wherein the first data link is an HDLC data link.
28. The system of claim 21 wherein the first device provides the gathered information to the third device.
29. The system of claim 28 wherein the third device utilizes the information from the first device to route packets from the fourth device to the second device.
30. The system of claim 21 , wherein the first and third devices are interconnected through at least one Virtual Private Network.