feat: flip swap mechanism — MD as primary, RST as override (Phase 1)

This is the first of three phases inverting the per-page swap mechanism
so MD becomes the canonical primary and RST becomes the rare override.

Phase 1 — file renames + conf.py exclude_patterns flip only:
- Rename docs/**/md-<stem>.md to docs/**/<stem>.md (drop md- prefix)
  for all 254 stems previously listed in docs/_swap.txt
- Rename docs/**/<stem>.rst to docs/**/rst-<stem>.rst (add rst- prefix)
  for the same 254 stems
- Repurpose docs/_swap.txt as docs/_rst_overrides.txt; initially empty
  comment-only since no pages need the RST fallback right now
- conf.py exclude_patterns flipped: rst-*.rst is now excluded by default
  instead of md-*.md
- conf.py runtime-artifact references updated to _rst_override_state.json
  and _md_exclude.txt (Phase 2 will rewrite swap_sources.py to produce
  these names; for now no swap script runs because overrides list is empty)

Phase 2 (next commit on this branch) will rewrite scripts/swap_sources.py
with inverted rename direction, delete scripts/import_myst.py + tests, and
update tests/test_swap_sources.py for the new semantics.

Phase 3 will be the cleanup pass and ready-for-review flip.

Generated by robots https://vyos.io

1 files changed, 35 insertions, 0 deletions

diff --git a/docs/vpp/configuration/dataplane/l2learn.md b/docs/vpp/configuration/dataplane/l2learn.md
new file mode 100644
index 00000000..2ce572a1
--- /dev/null
+++ b/docs/vpp/configuration/dataplane/l2learn.md
@@ -0,0 +1,35 @@
+---
+lastproofread: '2026-02-26'
+---
+
+(vpp-config-dataplane-l2learn)=
+
+```{include} /_include/need_improvement.txt
+```
+
+# VPP L2LEARN Configuration
+
+When VPP dataplane connects to an L2 domain, it learns MAC addresses of
+devices in the domain. By default, the number of MAC addresses it can
+learn is limited.
+
+You can configure the limit using the following command:
+
+```{cfgcmd} set vpp settings resource-allocation mac-limit \<value\>
+```
+
+This parameter sets the maximum number of MAC addresses that can be
+learned in the L2 domain. If you have many devices, you may need to
+increase this limit to ensure VPP learns all MAC addresses.
+
+## Potential Issues and Troubleshooting
+
+Improper L2LEARN configuration can lead to various issues, including:
+
+- MAC address learning failure in the L2 domain if the limit is set too
+  low
+- Increased packet loss or latency for devices that aren't learned
+- Overall dataplane instability when handling L2 traffic
+
+Consider increasing the L2LEARN limit if you experience issues with MAC
+address learning or if you have many devices in the L2 domain.