ARP packet processing method, communication system and device

• US 8,542,684 B2
• Filed: 11/06/2009
• Issued: 09/24/2013
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Li, Zhenhai
• Primary Examiner(s): Lee, Jae Y
• Assistant Examiner(s): GUADALUPE CRUZ, AIXA AMYR
• Application Number:
  US12/614,206
• Publication Number:
  US 20100054253A1
• Time in Patent Office: 1,418 Days
• Field of Search: None
• US Class Current: 370/392
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04L 63/1441 Countermeasures against malicious traffic countermeasures against attacks on cryptographic mechanisms H04L9/002

Abstract

An Address Resolution Protocol (ARP) packet processing method, a communication system and a device are disclosed. The method includes: receiving an ARP packet, and judging the type of the ARP packet; when the ARP packet is an ARP request, responding to the ARP request if an entry corresponding to the ARP request is found in a local ARP table; and when the ARP packet is an ARP response, reporting the ARP response if an entry corresponding to the ARP response is found in the local ARP table and a reporting parameter in the entry indicates permission of reporting; or discarding the ARP response if no entry corresponding to the ARP response is found in the ARP table.

Claims

1. An Address Resolution Protocol (ARP) packet processing method, comprising:

receiving, by a forwarding plane processor, an ARP packet generated by an external network device;

judging, by the forwarding plane processor, whether the received ARP packet is an ARP request or an ARP response;

searching an entry corresponding to the received ARP packet in a local ARP table;

if the received ARP packet is the ARP response, and if the entry corresponding to the ARP packet is in the local ARP table, determining if a reporting parameter in the entry corresponding to the received ARP packet indicates a permission of reporting;

if the reporting parameter indicates the permission of reporting, reporting, by the forwarding plane processor, the ARP response;

if the reporting parameter indicates no permission of reporting, limiting, by the forwarding plane processor, a transmission rate of the ARP response, reporting, by the forwarding plane processor, the ARP response to a control- plane processor, and

discarding, by the forwarding plane processor, the ARP response;

if the received ARP packet is the ARP response, and if no entry corresponding to the ARP packet is in the local ARP table, discarding, by the forwarding plane processor, the ARP response;

if the received ARP packet is the ARP request and if the entry corresponding to the received ARP packet is in the local ARP table, responding, by the forwarding plane processor, to the ARP request; and

judging, by the forwarding plane processor, whether a proxy ARP function is enabled on an interface that receives the ARP request if no entry corresponding to the ARP request is found in the ARP table;

if the proxy ARP function is enabled, limiting, by the forwarding plane processor, a transmission rate of the ARP request, and then reporting the AR P request to the control plane processor; and

if the proxy ARP function is not enabled, discarding, by the forwarding plane processor, the ARP request.

2. The ARP packet processing method of claim 1, further comprising:

if the received ARP packet is the ARP request,

searching, by the forwarding plane processor, the ARP table according to a port number of the ARP request, a Virtual Local Area Network (VLAN) ID, and a destination Internet Protocol (IP) address.

3. The ARP packet processing method of claim 1, wherein before responding, by the forwarding plane processor, to the ARP request, the method further comprises:

if the entry corresponding to the ARP request is neither an ARP entry of a gateway entry nor a proxy ARP entry, discarding, by the forwarding plane processor, the ARP request.

4. The ARP packet processing method of claim 1, further comprising:

if the received ARP packet is an ARP response, searching, by the forwarding plane processor, the ARP table according to a source Internet Protocol (IP) address of the ARP response.

5. The ARP packet processing method of claim 1, wherein after reporting, by the forwarding plane processor, the ARP response, the method further comprises:

modifying, by a control plane processor, the reporting parameter in the entry corresponding to the ARP response in the ARP table to no permission of reporting.

6. A communication system, comprising:

a forwarding plane processor configured to;

receive an Address Resolution Protocol (ARP) packet;

judge whether the received ARP packet is an ARP request or an ARP response;

search an entry corresponding to the ARP packet in a local ARP table;

if the received ARP packet is the ARP response, and if the entry corresponding to the ARP packet is in the local ARP table, determine if a reporting parameter in the entry corresponding to the received ARP packet indicates a permission of reporting;

if the reporting parameter indicates the permission of reporting, report the ARP response;

if the reporting parameter indicates no permission of reporting, limit a transmission rate of the ARP response, report the ARP response to a control plane processor, and discard the ARP response; and

if the received ARP packet is an ARP response, and if no entry corresponding to the ARP packet is in the local ARP table, discard the ARP response; and

if the ARP packet is the ARP request and if the entry corresponding to the received ARP packet is in the local ARP table, respond to the ARP request;

judge whether a proxy ARP function is enabled on an interface that receives the ARP request when the one or more processors find no entry corresponding to the received ARP request in the ARP table;

if the proxy ARP function is enabled, limit a transmission rate of the ARP request and report the ARP request to the control plane processor; and

if the proxy ARP function is not enabled, discard the ARP request

wherein the control plane processor is configured to receive the ARP request or the ARP response reported by the forwarding plane processor.

7. A forwarding plane processor, comprising:

one or more processors; and

a memory for storing instructions, which, when executed by the one or more processors, cause the one or more processors to;

receive an Address Resolution Protocol (ARP) packet from an external network device;

judge whether the received ARP packet is an ARP request or an ARP response;

search an entry corresponding to the received ARP packet in a local ARP table;

if the received ARP packet is the ARP response, and if the entry corresponding to the received ARP packet is in the local ARP table, determine if a reporting parameter in the entry corresponding to the received ARP packet indicates a permission of reporting;

if the reporting parameter indicates the permission of reporting, report the ARP response;

if the reporting parameter indicates no permission of reporting, limit a transmission rate of the ARP response, report the ARP response to a control plane processor, and discard the ARP response; and

if the received ARP packet is the ARP response, and if no entry corresponding to the received ARP packet is in the local ARP table, discard the ARP response; and

if the received ARP packet is the ARP request, and if the entry corresponding to the received ARP packet is in the local ARP table, respond to the ARP request;

judge whether a proxy ARP function is enabled on an interface that receives the ARP request when the one or more processors find no entry corresponding to the received ARP request in the ARP table;

if the proxy ARP function is enabled, limit a transmission rate of the ARP request and report the ARP request to the control plane processor; and

if the proxy ARP function is not enabled, discard the ARP request.