Monitoring flow activity on a network device

Patent metadata

Field	Value
Publication number	US-10958554-B2
Application number	US-201816108836-A
Country	US
Kind code	B2
Filing date	Aug 22, 2018
Priority date	Aug 22, 2018
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

Examples disclosed herein relate to monitoring flow activity on a network device. In an example, a neighbor table is maintained on a network device. The neighbor table may include a record of a neighbor network device and a hit bit corresponding to the neighbor network device. The hit bit may be used to represent a flow activity of the neighbor network device. A determination may be made whether a status of the hit bit corresponding to the neighbor network device is inactive. If the status of the hit bit is inactive, a flow entry corresponding to the neighbor network device may be deleted from an ASIC table on the network device.

First claim

The invention claimed is:

1. A method of monitoring flow activity on a network device, comprising:
maintaining a neighbor table on the network device, wherein the neighbor table includes a record of a neighbor network device and a hit bit corresponding to the neighbor network device, wherein the hit bit is used to represent a flow activity of the neighbor network device;
maintaining an entry in a media access control (MAC) address table on the network device, wherein the entry comprises a MAC address corresponding to an Internet Protocol (IP) address in the record of the neighbor network device and a last updated timestamp for the MAC address;
removing the MAC address from the MAC table in response to a determination that an aging period for the entry in the MAC address table is longer than a MAC aging time for the entry, wherein the determination is based on the last updated timestamp;
determining whether a status of the hit bit corresponding to the neighbor network device is inactive, wherein determining comprises:
determining, from the MAC address table on the network device, whether the MAC address is absent from the MAC address table longer than a pre-defined time period; and
in response to a determination that the MAC address corresponding to the IP address in the record of the neighbor network device is absent from the MAC address table longer than the pre-defined time period, indicating, in the neighbor table, the status of the hit bit corresponding to the neighbor network device as inactive, wherein the predefined time period is longer than the MAC aging time; and

in response to a determination that the status of the hit bit corresponding to the neighbor network device is inactive, deleting a flow entry corresponding to the neighbor network device from an application-specific integrated-circuit (ASIC) table on the network device.

2. The method of claim 1 , comprising:
adding a new flow entry corresponding to a new neighbor network device in the ASIC table, in place of the flow entry corresponding to the neighbor network device.

3. The method of claim 1 , wherein determining whether the MAC address corresponding to the IP address in the record of the neighbor network device is absent from the MAC address table longer than the pre-defined time period comprises:
determining whether a time period elapsed after the last updated timestamp for the MAC address is longer than the pre-defined time period.

4. The method of claim 1 , comprising:
updating the neighbor table on the network device, wherein updating comprises:
receiving a notification message from a kernel of the network device; and
updating the neighbor table on the network device based on the notification message.

5. The method of claim 4 , wherein the notification message includes information related to an addition of a new network device, a state change of the neighbor network device, and a deletion of an existing neighbor network device.

6. The method of claim 1 , wherein the pre-defined time is longer than the MAC address aging time defined for an entry in the MAC address table.

7. The method of claim 1 , comprising updating the record of the neighbor network device to indicate the MAC address in the neighbor table.

8. A network device, comprising:
a table engine to:
maintain a neighbor table on the network device, wherein the neighbor table includes a record of a neighbor network device and a hit bit corresponding to the neighbor network device, wherein the hit bit is used to represent a flow activity of the neighbor network device; and
maintain a MAC address table on the network device, wherein an entry in the MAC address table comprises a MAC address corresponding to an Internet Protocol (IP) address in the record of the neighbor network device and a last updated timestamp for the MAC address;
determine whether to remove the MAC address from the MAC table based on an aging period for the entry in the MAC address table and the last updated timestamp; and

a determination engine to:
determine whether a status of the hit bit corresponding to the neighbor network device is inactive, wherein the determination comprises:
determining, from the MAC address table, whether the MAC address corresponding to the IP address in the record of the neighbor network device, is absent from the MAC address table longer than a pre-defined time period; and
in response to a determination that the MAC address corresponding to the IP address in the record of the neighbor network device is absent from the MAC address table longer than the pre-defined time period, indicating, in the neighbor table, the status of the hit bit corresponding to the neighbor network device as inactive, wherein the predefined time period is longer than the MAC aging time;

in response to a determination that the status of the hit bit corresponding to the neighbor network device is inactive, delete a flow entry corresponding to the neighbor network device from an ASIC table on the network device; and
add a new flow entry corresponding to a new neighbor network device in the ASIC table.

9. The network device of claim 8 , wherein the neighbor table is an Open vSwitch Database (OVSDB) on the network device.

10. The network device of claim 8 , wherein the network device does not include an ASIC that supports the hit bit for indicating the flow activity of the neighbor network device.

11. The network device of claim 8 , wherein the record of the network device includes a source of the neighbor network device.

12. The network device of claim 8 , wherein the ASIC table represents an ASIC that does not support the hit bit for indicating the flow activity of the neighbor network device.

13. The network device of claim 8 , wherein the ASIC table includes a record of a flow entry for each neighbor network device.

14. A non-transitory machine-readable storage medium comprising instructions, the instructions executable by a processor to:
maintain a neighbor table on a network device, wherein the neighbor table includes a record of a neighbor network device and a hit bit corresponding to the neighbor network device, wherein the hit bit is used to represent a flow activity of the neighbor network device;
maintain an entry in a media access control (MAC) address table on the network device, wherein the entry comprises a MAC address corresponding to an Internet Protocol (IP) address in the record of the neighbor network device and a last updated timestamp for the MAC address;
remove the MAC address from the MAC table in response to a determination that an aging period for the entry in the MAC address table is longer than a MAC aging time for the entry, wherein the determination is based on the last updated timestamp;
determine whether a status of the hit bit corresponding to the neighbor network device is inactive, wherein the instructions to determine comprise instructions to:
determine, from the MAC address table, whether the MAC address corresponding to the IP address in the record of the neighbor network device is absent from the MAC address table longer than a pre-defined time period; and
in response to a determination that the MAC address corresponding to the IP address in the record of the neighbor network device, is absent from the MAC address table longer than the pre-defined time period, indicate, in the neighbor table, the status of the hit bit corresponding to the neighbor network device as inactive, wherein the predefined time period is longer than the MAC aging time; and

in response to a determination that the status of the hit bit corresponding to the neighbor network device is inactive, d

Assignees

• Hewlett Packard Entpr Dev Lp

Inventors

• Nandy Tathagata
• Majila Rajib

Classifications

• H04L45/02

  Topology update or discovery · CPC title

• H04L45/036

  Updating the topology between route computation elements, e.g. between OpenFlow controllers · CPC title

• H04L43/20

  the monitoring system or the monitored elements being virtualised, abstracted or software-defined entities, e.g. SDN or NFV · CPC title

• H04L43/0894 Primary

  Packet rate · CPC title

• H04L43/026 Primary

  using flow identification · CPC title