IP network for accomodating mobile users with incompatible network addressing

• US 6,865,613 B1
• Filed: 06/27/2002
• Issued: 03/08/2005
• Est. Priority Date: 03/15/1999
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Ng, Chi-Shing, Millet, Mark E.
• Primary Examiner(s): Barot, Bharat
• Application Number:
  US10/187,203
• Time in Patent Office: 985 Days
• Field of Search: 709200-203, 709217-218, 709/223, 709/227, 709238-239, 709245-246, 709249-250, 370253-254, 370351-356, 370400-401
• US Class Current: 709/245
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04L 61/25 of the same type
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

An flexible address translation method allows a computer network to automatically learn that a visiting node has attached and then automatically establish a virtual gateway so that the visiting node can communicate through the network with local nodes, other visiting nodes, and/or Internet sites. The network performs an address translation to enable the connectivity of the visiting node. The network maintains one or more globally unique outside addresses that point to it. When a visiting node connects to the network, the network translates the source address of packets from the node to a particular one of its outside addresses. The network also replaces destination addresses in packets received by the network that are addressed to the particular outside address. Specifically, the network replaces the globally unique outside address with the “home” address of the visiting node.

Claims

1. An apparatus configured to provide a network connection for a visiting node at a remote network, the visiting node being configured to connect through a home network that is remote from the remote network, the apparatus comprising:

one or more processors; and

a memory in communication with at least one of the processors,

wherein at least one of the processors and the memory is configured to provide an address translation list including one or more translation entries, each specifying a home IP address of the visiting node and a globally unique outside address,

wherein the globally unique outside address is provided by the remote network and the home IP address is the IP address of the visiting node on its home network, and

wherein at least one of the processors and the memory is configured to act as a remote network node on the remote network for a visiting node, which remote network node behaves as the default gateway for the visiting node by responding to a message from the visiting node addressed to a default gateway on the home network of the visiting node.

2. The apparatus of claim 1, wherein the remote network node sends a default gateway packet to the visiting node, which default gateway packet indicates that the remote network can handle Internet traffic from the visiting node.

3. The apparatus of claim 1, wherein an address translation entry specifies a destination IP address for node on the Internet with which the visiting node communicates.

4. The apparatus of claim 1, wherein at least one of the processors and the memory is configured to determine that the visiting node has made a Domain Name System request addressed to a home name server that is not on the remote network;

and then redirect the Domain Name Service request to a remote name server to which the remote network is configured to submit Domain Name Service requests.

5. The apparatus of claim 1, further comprising an operating system that configures the apparatus to perform address translation by switching the globally unique outside address and the home IP address on packets to and from the visiting node.

6. A computer program product comprising:

(a) a machine readable medium; and

(b) program instructions contained in the machine readable medium, the program instructions specifying a method for providing a network connection for a visiting node at a remote network, the visiting node being configured to connect through a home network that is remote from the remote network, the method comprising;

establishing a remote network node on the remote network for the visiting node by responding to a message from the visiting node addressed to a default gateway on the home network of the visiting node, which remote network node behaves as the default gateway for the visiting node; and

in a packet received at the remote network node, switching a home IP address of the visiting node with a globally unique outside address provided by the remote network.

7. The computer program product of claim 6, wherein establishing the remote network node comprises sending a default gateway packet to the visiting node, the default gateway packet indicating that the remote network can handle Internet traffic from the visiting node, and wherein the default gateway packet is a reply to a default gateway ARP packet sent by the visiting node.

8. The computer program product of claim 6, wherein switching the home IP address with a globally unique outside address takes place when the packet is sent from the visiting node, and wherein the source IP address of such packets is replaced with the globally unique outside address.

9. The computer program product of claim 6, wherein switching the home IP address with a globally unique outside address takes place when the packet has the globally unique outside address as a destination IP address, and wherein the destination IP address of the packet is replaced with the home IP address of the visiting node.

10. The computer program product of claim 6, further comprising program instructions for creating a translation entry specifying the home IP address of the visiting node and the globally unique outside address.

11. An apparatus configured to provide a network connection for a visiting node at a remote network, the visiting node being configured to connect through a home network that is remote from the remote network, the apparatus comprising:

means for establishing a remote network node on the remote network for the visiting node by responding to a message from the visiting node addressed to a default gateway on the home network of the visiting node, which remote network node behaves as the default gateway for the visiting node; and

means for switching, in a packet received at the remote network node, a home IP address of the visiting node with a globally unique outside address provided by the remote network.

12. The apparatus of claim 11, wherein the remote network node sends a default gateway packet to the visiting node, which default gateway packet indicating that the remote network can handle Internet traffic from the visiting node.

13. An apparatus configured to provide a network connection for a visiting node at a remote network, the visiting node being configured to connect to a default gateway through a home network that is remote from the remote network by using a home address, the apparatus comprising:

one or more processors; and

a memory in communication with at least one of the processors,

wherein at least one of the processors and the memory is configured to

receive a packet with the home address,

replace the home address in the packet with a globally unique address which corresponds to the home address, and

send the packet with the globally unique address through the remote network.

14. The apparatus of claim 13, wherein at least one of the processors and the memory is further configured to store a description which represents relationship between the home address and the globally unique address.

15. The apparatus of claim 13, wherein the description includes a list having an entry which represents the home address and the globally unique address.

16. A method of providing a network connection for a visiting node at a remote network, the visiting node being configured to connect through a home network that is remote from the remote network, the method comprising:

(a) receiving an ARP packet from the visiting node, which ARP packet is addressed to a default gateway for the visiting node;

(b) responding to the ARP packet in a manner mimicking the default gateway for the visiting node; and

(c) in a packet received at the remote network node, switching a home IP address of the visiting node with a globally unique outside address provided by the remote network.

17. The method of claim 16, wherein responding to the ARP packet comprises sending a packet, identifying a gateway address used by the remote network, to the visiting node, the default gateway packet indicating that the remote network can handle Internet traffic from the visiting node.

18. The method of claim 16, wherein switching the home IP address with a globally unique outside address takes place when the packet is sent from the visiting node, and wherein the source IP address of such packets is replaced with the globally unique outside address.

19. The method of claim 16, wherein switching the home IP address with a globally unique outside address takes place when the packet has the globally unique outside address as a destination IP address, and wherein the destination IP address of the packet is replaced with the home IP address of the visiting node.

20. The method of claim 16, further comprising creating a translation entry specifying the home IP address of the visiting node and the globally unique outside address.