Method and system for tracing packets in software defined networks

Patent metadata

Field	Value
Publication number	US-11522797-B2
Application number	US-201716635985-A
Country	US
Kind code	B2
Filing date	Aug 30, 2017
Priority date	Aug 30, 2017
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A method is implemented by a network device where the method performs a trace flow process in a packet processing pipeline of the network device. The packet processing pipeline includes a trace table and a forward table. The method encompasses forwarding a trace packet to the trace table, forwarding a copy of the trace packet to a trace analyzer in response to determining that a trace bit is set in the trace packet, forwarding the trace packet to the forward table, and determining a next stage of the packet processing pipeline based on trace packet meta data and a value stored in a trace register.

First claim

What is claimed is:

1. A method implemented by a network device, the method to perform a trace flow process in a packet processing pipeline of the network device, the packet processing pipeline including a set of flow tables defining actions and matching criteria, the set of flow tables including a trace table and a forward table, the method comprising:
storing by a first flow table in the set of flow tables a next destination for a trace packet into a trace register;
forwarding the trace packet, by the first flow table, to the trace table;
forwarding a copy of the trace packet and information on a plurality of flow tables in the set of flow tables traversed by the trace packet, by the trace table, to a trace analyzer to generate a trace, in response to the trace table determining that a trace bit is set in the trace packet;
forwarding, by the trace table, the trace packet to the forward table; and
determining, by the forward table, a next stage of the packet processing pipeline to forward the trace packet to, based on trace packet meta data and the next destination stored in the trace register indicating a next hop in the processing pipeline for the trace packet; and
replacing, in a flow table of the set of flow tables, a goto command having a first destination as an operand with a goto command with the trace table as the operand and a load command to place the first destination in the trace register.

2. The method of claim 1 , further comprising:
receiving the trace packet from a controller or a marking module; and
initiating processing of the trace packet at the first flow table of the packet processing pipeline.

3. The method of claim 1 , wherein the packet processing pipeline further includes a drop table, the method further comprising:
forwarding the trace packet to a drop table.

4. The method of claim 1 , wherein the meta data in the trace packet indicates a type of the next destination for the trace packet after the forward table.

5. A network device configured to implement a method to perform a trace flow process in a packet processing pipeline of the network device, the network device comprising:
a non-transitory machine-readable storage medium having stored therein a set of flow tables including a trace table and a forward table, the set of flow tables including flow entries having values to identify a trace packet and send the trace packet to the trace table; and
a processor to execute a packet processing pipeline including the trace table and the forward table, the processor to store a next destination for the trace packet into a trace register, to forward the trace packet to the trace table, to forward a copy of the trace packet and information on a plurality of flow tables in the set of flow tables traversed by the trace packet to a trace analyzer in response to determining that a trace bit is set in the trace packet, to forward the trace packet to the forward table, to determine a next stage of the packet processing pipeline to forward the trace packet to, based on trace packet meta data and the next destination stored in the trace register indicating a next hop in the processing pipeline for the trace packet, and to replace in a flow table of the set of flow tables a goto command having a first destination as an operand with a goto command with the trace table as the operand and a load command to place the first destination in the trace register.

6. The network device of claim 5 , wherein the processor is further configured to receive the trace packet from a controller or a marking module, and initiating processing of the trace packet at a first flow table of the packet processing pipeline.

7. The network device of claim 5 , wherein the packet processing pipeline further includes a drop table, the processor further configured to execute the trace flow by forwarding the trace packet to a drop table.

8. The network device of claim 5 , wherein the meta data in the trace packet indicates a type of the next destination for the trace packet after the forward table.

9. A computing device configured to execute a plurality of virtual machines, the plurality of virtual machines configured to provide network function virtualization (NFV), the plurality of virtual machines to implement a method to perform a trace flow process in a packet processing pipeline of the computing device, the computing device comprising:
a non-transitory machine-readable storage medium having stored therein a set of flow tables including a trace table and a forward table, the set of flow tables including flow entries having values to identify a trace packet and sent the trace packet to the trace table; and
a processor to execute the plurality of virtual machines, at least one virtual machine in the plurality of virtual machines to execute a packet processing pipeline including the trace table and the forward table, the at least one virtual machine to store a next destination for the trace packet into a trace register, to forward the trace packet to the trace table, forward a copy of the trace packet and information on a plurality of flow tables in the set of flow tables traversed by the trace packet to a trace analyzer in response to determining that a trace bit is set in the trace packet, forward the trace packet to the forward table, determine a next stage of the packet processing pipeline based on trace packet meta data and the next destination stored in the trace register indicating a next hop in the processing pipeline for the trace packet, and replace in a flow table of the set of flow tables a goto command having a first destination as an operand with a goto command with the trace table as the operand and a load command to place the first destination in the trace register.

10. The computing device of claim 9 , wherein the at least one virtual machine is further configured to receive the trace packet from a controller or a marking module, and initiating processing of the trace packet at a first flow table of the packet processing pipeline.

11. The computing device of claim 9 , wherein the at least one virtual machine further includes a drop table, the processor further configured to execute the trace flow by forwarding the trace packet to a drop table.

12. The computing device of claim 9 , wherein the meta data in the trace packet indicates a type of the next destination for the trace packet after the forward table.

13. A control plane device configured to implement a method to perform a trace flow process in a packet processing pipeline of a network device, the control plane device comprising:
a non-transitory machine-readable storage medium having stored therein a trace analyzer and a flow entry modifier; and
a processor coupled to the non-transitory machine-readable storage medium, the processor to execute the trace analyzer, the trace analyzer to receive at least one trace packet copy from a trace table of a node in a set of nodes in a data plane of a software defined network, the trace analyzer to determine a trace across a plurality of flow tables identifying each traversed flow table in the plurality of flow tables within a packet processing pipeline based on information provided by the node with the trace packet copy, the processor to execute the flow entry modifier, the flow entry modifier to replace in a flow table of the plurality of flow tables a goto command having a first destination as an operand with a goto command with the trace table as the operand and a load command to place the first destination in a trace register.

14. The control plane device of claim 13 , wherein the trace analyzer is further to determine a trace across mult

Assignees

• Ericsson Telefon Ab L M

Inventors

• C H Vyshakh Krishnan
• K Faseela
• Halpern Joel

Classifications

• H04L45/742 Primary

  Route cache; Operation thereof · CPC title

• G06F9/45558

  Hypervisor-specific management and integration aspects · CPC title

• H04L41/122

  of virtualised topologies, e.g. software-defined networks [SDN] or network function virtualisation [NFV] · 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

• G06F2009/45595

  Network integration; Enabling network access in virtual machine instances · CPC title