Update `ECMP hashing for GUE flows with IPv4|UDP outer header on deca…

[sachendras]

Change v4 transport with v6 transport.

[gemini-code-assist]

Summary of Changes

Hello @sachendras, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request updates the documentation and configuration examples for GUEv1 decapsulation and ECMP hashing tests. The primary goal is to transition the test scenarios from using IPv4 as the outer transport header to IPv6, ensuring that the test cases and associated configurations accurately reflect IPv6-based GUE deployments and their expected behavior on decapsulating nodes.

Highlights

• Updated GUEv1 Hashing Description: The README's summary now explicitly states that the outer header for GUEv1 encapsulated packets used for hashing on decapsulating nodes is 'IPv6 | UDP', changing from the previous 'IPv4 | UDP'.
• IPv6 Decapsulation Configuration: The test setup instructions have been updated to configure the DUT as a decapsulation node for 'IPv6|UDP (GUE v1)' using 'DUT-DECAP-Address-V6', replacing the generic 'IP|UDP' and 'DUT-DECAP-Address'.
• Traffic Flow Table Updates: All entries in the traffic flow table that previously referenced 'ATE1-port IPv4 addr' and 'DUT-DECAP-Address' for the outer header of GUEv1 encapsulation have been updated to use 'ATE1-port IPv6 addr' and 'DUT-DECAP-Address-V6' or 'ATE2-port-Address IPv6 addr', ensuring consistency with IPv6 transport.
• Test Case Renaming and Validation Updates: Test cases PF-1.22.1 and PF-1.22.2 have been renamed to reflect 'ipv6 decap address' and their validation steps now refer to 'DUT-DECAP-Address-V6' and 'decap IPv6 address' for accuracy.
• OpenConfig Policy Forwarding Configuration: The example JSON configuration for policy forwarding has been significantly updated to define an IPv6 prefix set ('dst_prefix_v6_gue') and configure the decapsulation policy rule to use this IPv6 prefix set and protocol 'IP_UDP' under the 'ipv6' section, replacing the previous 'ipv4' configuration.
• OpenConfig Path Coverage: The OpenConfig Path and RPC Coverage section has been revised to remove IPv4-specific paths and include new paths related to IPv6 defined-sets and IPv6 policy forwarding rules.

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[OpenConfigBot]

Pull Request Functional Test Report for #4960 / 6153606

Virtual Devices

Device	Test	Test Documentation	Job	Raw Log
Arista cEOS		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload	ef052e7f	Log
Cisco 8000E		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload	70a29f68	Log
Cisco XRd		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload	9c690e59	Log
Juniper ncPTX		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload	e6bbf371	Log
Nokia SR Linux		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload	044ff43d	Log
Openconfig Lemming		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload	67a953a8	Log

Hardware Devices

Device	Test	Test Documentation	Raw Log
Arista 7808		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload
Cisco 8808		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload
Juniper PTX10008		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload
Nokia 7250 IXR-10e		PF-1.22: GUEv1 Decapsulation and ECMP test for IPv4 and IPv6 payload

Help

[gemini-code-assist]

Code Review

This pull request updates the README.md to change the GUE decapsulation test from using an IPv4 outer header to an IPv6 outer header. While the documentation changes are mostly correct, there are a couple of inconsistencies in the updated tables and paths that need to be addressed. More importantly, the Go test code in this directory has not been updated and still implements the test with an IPv4 outer header. This creates a discrepancy between the test plan (README.md) and the implementation, which violates the repository's contribution guidelines stating that 'Test code must follow the steps documented in the test README.md'. To resolve this, please either update the Go test code to match the new README in this PR, or revert the README changes and create a new PR that updates both the documentation and the code together.

[coveralls]

Pull Request Test Coverage Report for Build 20484278921

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 10.03%

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Totals
Change from base Build 20479668220:	0.0%
Covered Lines:	2227
Relevant Lines:	22203

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💛 - Coveralls

[sachendras]

/gemini review

[gemini-code-assist]

Code Review

This pull request aims to update the GUE decapsulation test to use an IPv6 outer header instead of IPv4. However, there is a critical issue. While the documentation in README.md has been updated, the corresponding test implementation in ipv4_guev1_decap_and_hashing_test.go appears to be unchanged and still implements the test using IPv4. This is a violation of the repository's contribution guidelines, which state that test code must follow the test's README.md (see CONTRIBUTING.md, line 49). The test code must be updated to match the new documentation for this PR to be valid. I've also left some comments on the README.md to fix a few inconsistencies. For better long-term maintainability, please also consider renaming the test directory and file from ipv4_... to ipv6_... to accurately reflect its new purpose.

[gemini-code-assist]

There appears to be a typo in the description for Flow 11. The inner packet is specified as IPv6|TCP, but the source and destination addresses are H1v4 address and H4v4 address. For consistency with other IPv6 flows (like Flow 12), these should likely be H1v6 address and H4v6 address.

[sachendras]

/gemini review

[gemini-code-assist]

Code Review

This pull request is incomplete. While the README.md has been updated to change the GUE decapsulation test from using an IPv4 outer header to an IPv6 outer header, the actual test implementation in ipv4_guev1_decap_and_hashing_test.go has not been modified. The Go code still configures and sends GUE packets with an IPv4 outer header, creating a critical discrepancy between the test plan and the code. The helper functions in internal/cfgplugins/policyforwarding.go also appear to be missing the necessary updates for IPv6. Please update the Go files to fully implement the IPv6 logic as described in the README.md. Additionally, for better maintainability, consider renaming the test directory to reflect that the test now focuses on IPv6.