# US 10,484,272 B2 · Packet forwarding in RPR network

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- Number: US 10,484,272 B2
- Document ID: US10484272B2
- Status: Granted
- Kind: B2
- Application number: 15/505,413
- Filed: 2015-08-18
- Published: 2017-09-14
- Granted: 2019-11-19
- Earliest claimed: 2014-08-20
- Assignees: Hewlett Packard Enterprise Development LP
- Applicants: Hewlett Packard Enterprise Development LP
- Inventors: Wenjun Du; Zhixin Xiong; Jiabing Wang
- Web page: https://patentgrep.com/patent/US10484272B2

## CPC

- H04L 45/32: {Flooding (denial of service attacks H04L63/1458)}
- H04J 3/085: {for ring networks, e.g. SDH/SONET rings, self-healing rings, meashed SDH/SONET networks}
- H04J 14/0287: {Protection in WDM systems}
- H04L 12/437: Ring fault isolation or reconfiguration {(for SDH/SONET ring networks H04J3/085)}
- H04L 45/66: {Layer 2 routing, e.g. in Ethernet based MAN's}
- H04L 45/745: Address table lookup; Address filtering
- H04Q 11/0066: {Provisions for optical burst or packet networks}
- H04Q 2011/0016: {using wavelength multiplexing or demultiplexing}
- H04Q 2011/0073: {Provisions for forwarding or routing, e.g. lookup tables}
- H04Q 2011/0081: {Fault tolerance; Redundancy; Recovery; Reconfigurability}
- H04Q 2011/0092: {Ring}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S)
- H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W)

## Abstract

A network device in a RPR network receives a RPR flooding data packet sent by another network device in the RPR network, determines whether a next-hop network device of the RPR flooding data packet is a source network device sending the RPR flooding data packet, and strips the RPR flooding data packet when determining that the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet.

## Claims

### Claim 1

A packet forwarding method in a Resilient Packet Ring (RPR) network, applied to a network device in the RPR network and comprising:
receiving a RPR flooding data packet sent by another network device in the RPR network;
determining whether a next-hop network device of the RPR flooding data packet is a source network device sending the RPR flooding data packet;
stripping the RPR flooding data packet when determining that the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet; and
performing RPR encapsulation for a flooding data packet and setting a Time to Live (TTL) value as the number of network devices in the RPRR network subtracted by 1 to generate a RPR flooding data packet; and
forwarding the generated RPR flooding data packet.

### Claim 2 (depends on 1)

The method of claim 1, wherein determining whether the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet comprises:
determining a Media Access Control (MAC) address of the next-hop network device according to a local ring network topology table;
determining whether the MAC address of the next-hop network device is a source MAC address of the RPR flooding data packet; and
determining that the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet when determining that the MAC address of the next-hop network device is the source MAC address of the RPR flooding data packet; and determining that the next-hop network device of the RPR flooding data packet is not the source network device sending the RPR flooding data packet when determining that the MAC address of the next-hop network device is not the source MAC address of the RPR flooding data packet.

### Claim 3 (depends on 1)

The method of claim 1, after determining whether the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet, further comprising:
when determining that the next-hop network device of the RPR flooding data packet is not the source network device sending the RPR flooding data packet and a TTL value of the RPR flooding data packet is larger than 1, transiting the RPR flooding data packet.

### Claim 4

A packet forwarding apparatus in a Resilient Packet Ring (RPR) network, comprising a processor and a non-transitory storage;
the non-transitory storage is to store machine readable instructions, comprising receiving instructions, determining instructions and processing instructions;
the processor is to read the receiving instructions stored in the non-transitory storage to perform a process of: receiving a RPR flooding data packet from another network device in the RPR network;
the processor is further to read the determining instructions stored in the non-transitory storage to perform a process of: determining whether a next-hop network device of the RPR flooding data packet is a source network device sending the RPR flooding data packet, and determining that the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet when determining that the MAC address of the next-hop network device is the source MAC address of the RPR flooding data packet and determining that the next-hop network device of the RPRR flooding data packet is not the source network device sending the RPR flooding data packet when determining that the MAC address of the next-hop network device is not the source MAC address of the RPR flooding data packet; and
the processor is further to read the processing instructions stored in the non-transitory storage to perform a process of: stripping the RPR flooding data packet when the determining that the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet.

### Claim 5 (depends on 4)

The apparatus of claim 4, wherein the machine readable instructions further comprise encapsulating instructions and sending instructions;
the processor is further to read the encapsulating instructions stored in the non-transitory storage to perform a process of: performing RPR encapsulation for a flooding data packet and setting a Time To Live (TTL) value as the number of network devices in the RPR network to generate a RPR flooding data packet; and
the processor is further to read the sending instructions stored in the non-transitory storage to perform a process of: forwarding the generated RPR flooding data packet.

### Claim 6 (depends on 4)

The apparatus of claim 4, wherein the processor is further to read the sending instructions stored in the non-transitory storage to perform a process of: transiting the RPR flooding data packet when determining that the next-hop network device of the RPR flooding data packet is not the source network device sending the RPR flooding data packet and a TTL value of the RPR flooding data packet is larger than 1.

### Claim 7

A non-transitory computer-readable medium containing instructions to direct a processor to:
determine whether a next-hop network device of a received RPR flooding data packet is a source network device sending the RPR flooding data packet;
strip the RPR flooding data packet when determining that the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet; and
perform RPR encapsulation for a flooding data packet and setting a Time To Live (TTL) value as the number of network devices in the RPR network subtracted by 1 to generate a RPR flooding data packet; and
forward the generated RPR flooding data packet.

### Claim 8 (depends on 7)

The medium of claim 7, wherein to determine whether the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet, the instructions are to further direct the processor to:
determine a Media Access Control (MAC) address of the next-hop network device according to a local ring network topology table;
determine whether the MAC address of the next-hop network device is a source MAC address of the RPR flooding data packet; and
determine that the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet when determining that the MAC address of the next-hop network device is the source MAC address of the RPR flooding data packet; and determining that the next-hop network device of the RPR flooding data packet is not the source network device sending the RPR flooding data packet when determining that the MAC address of the next-hop network device is not the source MAC address of the RPR flooding data packet.

### Claim 9 (depends on 7)

The medium of claim 7, wherein after determining whether the next-hop network device of the RPR flooding data packet is the source network device sending the RPR flooding data packet, the instructions are to direct the processor to:
determine whether the next-hop network device of the RPR flooding data packet is not the source network device sending the RPR flooding data packet and a TTL value of the RPR flooding data packet is larger than 1; and
transit the RPR flooding data packet.