Automatic discovery of maximum transmission unit size for a software defined network

Patent metadata

Field	Value
Publication number	US-10581749-B2
Application number	US-201715796885-A
Country	US
Kind code	B2
Filing date	Oct 30, 2017
Priority date	Jul 13, 2017
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

The technology disclosed herein enables the automatic discovery of MTU size across a software defined network (SDN). In a particular embodiment, a method provides, in a management plane of the SDN, receiving a first MTU request from a first endpoint of the SDN that indicates a second endpoint of the SDN to which the first endpoint will transfer first data. The method further provides tracing a first path through the SDN for the first data between the first endpoint and the second endpoint, determining the smallest MTU along the first path, and setting a first MTU to a value less than or equal to the smallest MTU along the first path. The method also includes providing the first MTU to the first endpoint.

First claim

What is claimed is:

1. A method of discovering a maximum transmission unit (MTU) across a software defined network (SDN), the method comprising:
in a management plane of the SDN:
receiving a first MTU request from a first endpoint of the SDN that indicates a second endpoint of the SDN to which the first endpoint will transfer first data;
tracing a first path through the SDN for the first data between the first endpoint and the second endpoint;
determining the smallest MTU along the first path;
determining an amount of metadata required for network overhead when transferring data between the first endpoint and the second endpoint, wherein the network overhead includes metadata for a network tunnel between the first endpoint and the second endpoint;
setting a first MTU to a value less than or equal to the smallest MTU along the first path less the amount of metadata; and
providing the first MTU to the first endpoint.

2. The method of claim 1 , wherein the first endpoint transfers the first data to the second endpoint using the first MTU.

3. The method of claim 1 , wherein the network tunnel comprises a Virtual Extensible Local Area Network (VXLAN) or Geneve tunnel.

4. The method of claim 1 , wherein the network overhead includes data necessary for one or more protocols in the Internet Protocol Security (IPsec) suite of protocols.

5. The method of claim 1 , wherein the first endpoint transfers the first MTU request to the management plane upon receiving the first data from a virtual machine.

6. The method of claim 5 , wherein the first endpoint instructs the virtual machine to resend the first data using the first MTU when the first data does not comply with the first MTU.

7. The method of claim 1 , wherein the first endpoint stores the first MTU for use with subsequent data between the first endpoint and the second endpoint.

8. The method of claim 1 , wherein the first endpoint probes a physical network path corresponding to the first path to determine whether a MTU of an element on the physical network path decreases the first MTU.

9. A method of discovering a maximum transmission unit (MTU) across a software defined network (SDN), the method comprising:
in a management plane of the SDN:
receiving a first MTU request from a first endpoint of the SDN that indicates a second endpoint of the SDN to which the first endpoint will transfer first data;
tracing a first path through the SDN for the first data between the first endpoint and the second endpoint;
determining the smallest MTU along the first path;
receiving first descriptive information from the first endpoint that describes the first data;
determining an amount of metadata required for network overhead when transferring data between the first endpoint and the second endpoint based on the descriptive information, wherein different descriptive information results in different amounts of metadata required for the network overhead;
setting a first MTU to a value less than or equal to the smallest MTU along the first path less the amount of metadata; and
providing the first MTU to the first endpoint.

10. A system of discovering a maximum transmission unit (MTU) across a software defined network (SDN), the system comprising: one or more computer readable storage media; a processing system with processing circuitry operatively coupled with the one or more computer readable storage media; and program instructions stored on the one or more computer readable storage media that, when read and executed by the processing system, direct the processing system to:
provide a management plane of the SDN;
in the management plane:
receive a first MTU request from a first endpoint of the SDN that indicates a second endpoint of the SDN to which the first endpoint will transfer first data;
trace a first path through the SDN for the first data between the first endpoint and the second endpoint;
determine the smallest MTU along the first path;
determine an amount of metadata required for network overhead when transferring data between the first endpoint and the second endpoint, wherein the network overhead includes metadata for a network tunnel between the first endpoint and the second endpoint;
set a first MTU to a value less than or equal to the smallest MTU along the first path less the amount of metadata; and
provide the first MTU to the first endpoint.

11. The system of claim 10 , wherein the first endpoint transfers the first data to the second endpoint using the first MTU.

12. The system of claim 10 , wherein the network tunnel comprises a Virtual Extensible Local Area Network (VXLAN) or Geneve tunnel.

13. The system of claim 10 , wherein the network overhead includes data necessary for one or more protocols in the Internet Protocol Security (IPsec) suite of protocols.

14. The system of claim 10 , wherein the first endpoint transfers the first MTU request to the management plane upon receiving the first data from a virtual machine.

15. The system of claim 14 , wherein the first endpoint instructs the virtual machine to resend the first data using the first MTU when the first data does not comply with the first MTU.

16. The system of claim 10 , wherein the first endpoint stores the first MTU for use with subsequent data between the first endpoint and the second endpoint.

17. The system of claim 10 , wherein the first endpoint probes a physical network path corresponding to the first path to determine whether a MTU of an element on the physical network path decreases the first MTU.

18. A system of discovering a maximum transmission unit (MTU) across a software defined network (SDN), the system comprising: one or more computer readable storage media; a processing system with processing circuitry operatively coupled with the one or more computer readable storage media; and program instructions stored on the one or more computer readable storage media that, when read and executed by the processing system, direct the processing system to:
provide a management plane of the SDN;
in the management plane:
receive a first MTU request from a first endpoint of the SDN that indicates a second endpoint of the SDN to which the first endpoint will transfer first data;
trace a first path through the SDN for the first data between the first endpoint and the second endpoint;
determine the smallest MTU along the first path;
receive first descriptive information from the first endpoint that describes the first data;
determine an amount of metadata required for network overhead when transferring data between the first endpoint and the second endpoint based on the descriptive information, wherein different descriptive information results in different amounts of metadata required for the network overhead;
set a first MTU to a value less than or equal to the smallest MTU along the first path less the amount of metadata; and
provide the first MTU to the first endpoint.

19. A system of discovering a maximum transmission unit (MTU) across a software defined network (SDN), the system comprising: one or more computer readable storage media; a processing system with processing circuitry operatively coupled with the one or more computer readable storage media; and program instructions stored on the one or more computer readable storage media that, when read and executed by the processing system, direct the processing system to:
provide a first endpoint of the SDN;
in the first endpoint:
transfer a first MTU request to a management plane of the SDN that indicates a second endpoint of the SD

Assignees

• Nicira Inc

Inventors

• Kumar Vasantha
• Kasbe Sandeep

Classifications

• H04L63/20

  for managing network security; network security policies in general (filtering policies H04L63/0227) · CPC title

• H04L63/029

  Firewall traversal, e.g. tunnelling or, creating pinholes · CPC title

• H04L45/64

  using an overlay routing layer · CPC title

• H04L47/36

  by determining packet size, e.g. maximum transfer unit [MTU] · CPC title

• H04L63/164

  at the network layer · CPC title