Forwarding information to forward data to proxy devices

Patent metadata

Field	Value
Publication number	US-10616175-B2
Application number	US-201815967851-A
Country	US
Kind code	B2
Filing date	May 1, 2018
Priority date	May 1, 2018
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

In some examples, a switch includes a first communication interface to communicate with a first device, a second communication interface to communicate with a proxy device enabled to perform proxy address resolution, and a processor to receive a first data packet from the first device targeted to a first layer 3 network address, send, to the proxy device, an address resolution request to obtain a layer 2 network address corresponding to the first layer 3 network address, and responsive to receiving a response to the address resolution request, update a forwarding information structure to refer to a layer 3 network address of the proxy device, the forwarding information structure useable to forward a second data packet to the proxy device for transmission of the second data packet to a destination device.

First claim

What is claimed is:

1. A switch comprising:
a first communication interface to communicate with a first device;
a second communication interface to communicate with a proxy device enabled to perform proxy address resolution; and
a processor to:
receive a first data packet from the first device targeted to a first layer 3 network address,
send, to the proxy device, an address resolution request to obtain a layer 2 network address corresponding to the first layer 3 network address, and
responsive to receiving a response to the address resolution request, add an entry in a forwarding information structure, wherein the added entry in the forwarding information structure associates a predetermined route to a layer 3 network address of the proxy device, wherein the added entry in the forwarding information structure is useable to forward a second data packet to the proxy device for transmission of the second data packet to a destination device, wherein a second layer 3 network address targeted by the second data packet is different from the first layer 3 network address targeted by the first data packet, and wherein the processor is configured to forward the second data packet without sending an address resolution request to obtain a layer 2 network address corresponding to the second layer 3 network address.

2. The switch of claim 1 , wherein the processor is to:
for a plurality of layer 3 network addresses of destination devices separate from the proxy device, maintain an address resolution information entry mapping a layer 3 network address of the plurality of layer 3 network addresses to a layer 2 network address of the proxy device received by the switch, and
use the forwarding information structure to forward, to the proxy device, data packets targeted to the plurality of layer 3 network addresses.

3. The switch of claim 2 , wherein the processor is to:
add the address resolution information entry responsive to information in the response to the address resolution request.

4. The switch of claim 2 , further comprising a ternary content-addressable memory to store the address resolution information entry.

5. The switch of claim 2 , wherein the address resolution request comprises an Address Resolution Protocol (ARP) request,
wherein the proxy address resolution comprises a proxy ARP operation to respond to the ARP request with the layer 2 network address of the proxy device, and
wherein the address resolution information entry comprises an entry of an ARP table.

6. The switch of claim 2 , wherein the first device is on a first network, the destination devices are on a second network, and the proxy device is at a border between the first and second networks.

7. The switch of claim 1 , wherein the forwarding information structure comprises a Forwarding Information Base (FIB) table that correlates an Internet Protocol (IP) route to a next-hop address comprising the layer 3 network address of the proxy device.

8. The switch of claim 7 ,
wherein the processor is to map the first and second layer 3 network addresses to the IP route using rule information.

9. The switch of claim 8 , wherein the IP route is a first IP route, and wherein the processor is to:
receive a further data packet from a device targeted to a third layer 3 network address,
map the third layer 3 network address to a second IP route using the rule information,
send, to a second proxy device enabled to perform proxy address resolution, a second address resolution request to obtain a layer 2 network address corresponding to the third layer 3 network address, and
responsive to receiving a response to the second address resolution request, update the FIB table to add another entry that refers to a layer 3 network address of the second proxy device.

10. The switch of claim 1 , wherein a respective layer 3 network address comprises an Internet Protocol (IP) address.

11. The switch of claim 1 , wherein a respective layer 2 network address comprises a Medium Access Control (MAC) address.

12. A non-transitory machine-readable storage medium storing instructions that upon execution cause a switch to:
receive data from a first device targeted to layer 3 network address of a first destination device;
send, to a proxy device separate from the destination device and enabled to perform proxy address resolution, an address resolution request to obtain a layer 2 network address corresponding to the layer 3 network address; and
responsive to receiving a response to the address resolution request from the proxy device, add an entry in a forwarding information structure, wherein the added entry in the forwarding information structure associates a predetermined route to a layer 3 network address of the proxy device, wherein the added entry in the forwarding information structure is useable to forward subsequent data to the proxy device for transmission of the subsequent data to a second destination device, wherein a second layer 3 network address targeted by the second data packet is different from the first layer 3 network address targeted by the first data packet, and wherein the switch is further configured to forward the second data packet without sending an address resolution request to obtain a layer 2 network address corresponding to the second layer 3 network address.

13. The non-transitory machine-readable storage medium of claim 12 , wherein first device is on a first network, the first and second destination devices are on a second network, and the proxy device is at a border between the first and second networks.

14. The non-transitory machine-readable storage medium of claim 13 , wherein the instructions upon execution cause the switch to:
add, responsive to the response to the address resolution request, an entry to an address resolution table, the entry mapping the layer 3 network address of the first destination device to the layer 2 network address of the proxy device,
wherein not sending the address resolution request for the second layer 3 network address avoids adding an entry to the address resolution table for the second layer 3 network address.

15. The non-transitory machine-readable storage medium of claim 14 , wherein the address resolution table comprises an Address Resolution Protocol (ARP) table.

16. The non-transitory machine-readable storage medium of claim 12 , wherein the forwarding information structure comprises a Forwarding Information Base (FIB) table that correlates an Internet Protocol (IP) route to a next-hop address comprising the layer 3 network address of the proxy device.

17. A method comprising:
receiving, by a switch, a first data packet from a first device targeted to first Internet Protocol (IP) address of a first destination device;
sending, by the switch to a proxy device separate from the first destination device and enabled to perform proxy address resolution, an address resolution request to obtain, based on performing the proxy address resolution, a Medium Access Control (MAC) address corresponding to the first IP address;
responsive to a response to the address resolution request:
adding, by the switch, an entry to an address resolution table, and
adding an entry in a forwarding information structure, wherein the added entry in the forwarding information structure associates a predetermined route to an IP address of the proxy device; and
using the forwarding information structure to forward a second data packet from the first device or another device to the proxy device for transmission of the second data packet to a second destination device, wherein a

Assignees

• Hewlett Packard Entpr Dev Lp

Inventors

• Raj Anil
• Gopinathan Nair Saraswathy Amma Prasanth
• Devarajan Venkatavaradhan

Classifications

• H04L47/17

  Interaction among intermediate nodes, e.g. hop by hop · CPC title

• H04L69/324

  in the data link layer [OSI layer 2], e.g. HDLC · CPC title

• H04L61/103 Primary

  across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP] · CPC title

• H04L69/325

  in the network layer [OSI layer 3], e.g. X.25 (H04L69/16 takes precedence) · CPC title

• H04L45/745

  Address table lookup; Address filtering · CPC title