mlxsw T8878: add noudpcsum vxlan option

[scottlaird]

Change Summary

Apply documentation updates for T8878, adding set interfaces vxlan <interface> parameters noudpcsum.

Related Task(s)

• https://vyos.dev/T8878

Related PR(s)

vyos/vyos-1x#5201

Backport

Checklist:

• I have read the CONTRIBUTING document

[coderabbitai]

📝 Walkthrough

Walkthrough

Documentation for VXLAN interface configuration in docs/configuration/interfaces/vxlan.md was updated to add the noudpcsum parameter. The new section explains that UDP checksums should be disabled on VXLAN interfaces for hardware-accelerated VXLAN offloading scenarios where VyOS-generated checksums must be turned off.

Changes

VXLAN Parameter Documentation

Layer / File(s)	Summary
noudpcsum parameter documentation docs/configuration/interfaces/vxlan.md	Added documentation section (lines 110–116) for the set interfaces vxlan <interface> parameters noudpcsum option, explaining that UDP checksums must be disabled for hardware-accelerated VXLAN offload compatibility.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	Title clearly references T8878 task and the specific feature being documented (noudpcsum VXLAN option), directly matching the changeset.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description check	✅ Passed	The PR description directly relates to the changeset, specifying the documentation update for T8878 adding the noudpcsum VXLAN parameter.

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✨ Finishing Touches

✨ Simplify code

• Create PR with simplified code

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[andamasov]

Retriggering AI Validation via close+reopen — the workflow on rolling was just updated (vyos-documentation#2063) to allow Pass 2 review on fork-authored PRs. gh run rerun would replay the pre-fix workflow file, so close+reopen is the mechanism that picks up the new pull_request_target workflow on this PR's existing head SHA. No action needed from you.

[github-actions]

Claude finished @andamasov's task in 1m 37s —— View job

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VyOS Documentation Review

• Read pass1-findings.json
• Read changed file
• Verify against vyos-1x source (current)
• Post review summary

Issues

• WARNING — docs/configuration/interfaces/vxlan.md:110 — set interfaces vxlan <interface> parameters noudpcsum is not present in vyos-1x current. The parameters node in interface-definitions/interfaces_vxlan.xml.in defines external, nolearning, neighbor-suppress, and vni-filter; a repo-wide grep for noudpcsum/udpcsum returns zero matches in XML or Python. The referenced vyos-1x#5201 appears not yet merged. Inline comment posted.
• INFO — Wording: "VyOS's checksums" is imprecise — these are kernel-generated UDP checksums on the outer VXLAN packet. Suggested rewording in the inline comment.

Needs Verification

• Whether vyos-1x#5201 has landed in current since this PR was opened (May 16). If yes, the WARNING above can be dismissed. If no, this docs PR should wait for that merge to avoid documenting a non-existent CLI command on rolling.

Stats

• Validated 1 MyST file.
• Skipped 0 RST files awaiting MyST migration.
• Files reviewed: 1 (docs/configuration/interfaces/vxlan.md).
• Commands checked: 1 (interfaces vxlan parameters noudpcsum).
• Branch reviewed: rolling (vyos-1x: current).
  · Branch: push-ruksqtprxxwr

[github-actions]

WARNING — CLI path not yet present in vyos-1x current

Doc says: set interfaces vxlan <interface> parameters noudpcsum
Source (.vyos-1x/interface-definitions/interfaces_vxlan.xml.in): the parameters node defines external, nolearning, neighbor-suppress, and vni-filter, but no noudpcsum leafNode. A repo-wide grep for noudpcsum / udpcsum in .vyos-1x/ returns zero matches (XML or Python).
Branch: rolling (vyos-1x: current)

The referenced vyos-1x PR vyos/vyos-1x#5201 appears not yet merged into the current branch this docs PR targets. Once that PR merges, this documentation will be accurate. Worth confirming the merge has landed before this docs PR is merged, otherwise the docs will describe a command that does not exist in the running VyOS image.

Minor wording nit: "VyOS's checksums" — these are kernel-generated UDP checksums on VXLAN-encapsulated packets, not something VyOS itself produces. Consider: "…require that UDP checksums on the outer VXLAN packet be disabled."