Network diagnosis in software-defined networking (SDN) environments

A non-transitory computer-readable storage medium that includes a set of instructions which, in response to execution by a processor of a first computer system, cause the processor to perform a method of network diagnosis, wherein the method comprises:

• detecting an egress packet having an inner header that is addressed from a first virtualized computing instance to a second virtualized computing instance;
• determining, by one or more logical forwarding elements supported by the first computer system, whether each of multiple network issues is detected for the egress packet or a datapath between the first virtualized computing instance and the second virtualized computing instance;
• generating network diagnosis code information specifying whether each of the multiple network issues is detected or not detected, wherein the network diagnosis code information specifies:
• a first code that indicates whether or not there is detection of a first network issue from the multiple network issues and a second code that indicates whether or not there is detection of a second network issue from the multiple network issues, wherein the second code is concatenated with the first code in the network diagnosis code information, wherein the network diagnosis code information includes a plurality of bits at a respective plurality of bit positions, wherein the first code is indicated at a first bit position of the plurality of bit positions, and wherein the second code is concatenated with the first code by being indicated at a second bit position of the plurality of bit positions;
• generating an encapsulated packet by encapsulating the egress packet with an outer header that specifies the network diagnosis code information having the concatenated first and second codes and is addressed from the first computer system to a second computer system;
• and
• sending the encapsulated packet towards the second virtualized computing instance to cause a second computer system to perform one or more remediation actions based on the network diagnosis code information.

A computer system, comprising:

• a processor;
• and
• a non-transitory computer-readable medium having stored thereon instructions that, in response to execution by the processor, cause the processor to:
• detect an egress packet having an inner header that is addressed from a first virtualized computing instance to a second virtualized computing instance;
• determine, by one or more logical forwarding elements supported by the computer system, whether each of multiple network issues is detected for the egress packet or a datapath between the first virtualized computing instance and the second virtualized computing instance;
• generate network diagnosis code information specifying whether each of the multiple network issues is detected or not detected, wherein the network diagnosis code information specifies:
• a first code that indicates whether or not there is detection of a first network issue from the multiple network issues and a second code that indicates whether or not there is detection of a second network issue from the multiple network issues, wherein the second code is concatenated with the first code in the network diagnosis code information, wherein the network diagnosis code information includes a plurality of bits at a respective plurality of bit positions, wherein the first code is indicated at a first bit position of the plurality of bit positions, and wherein the second code is concatenated with the first code by being indicated at a second bit position of the plurality of bit positions;
• generate an encapsulated packet by encapsulating the egress packet with an outer header that specifies the network diagnosis code information having the concatenated first and second codes and is addressed from the computer system to a next hop;
• and
• send the encapsulated packet towards the second virtualized computing instance to cause the next hop to perform one or more remediation actions based on the network diagnosis code information.