From 19e18753c1ca97ffc68566f4852444f341e0319c Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Thu, 22 Dec 2022 19:23:51 -0800
Subject: [PATCH] [routing-manager] add feature to skip NS probe with router on
 same device (#8563)

This commit adds a new behavior in `RoutingManager` to skip performing
NS probe with a router with an address belonging to device infra
interface itself. This addresses the situation where platform may not
be be able to receive and pass the NA message responses from device
itself.
---
 src/core/border_router/routing_manager.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/core/border_router/routing_manager.cpp b/src/core/border_router/routing_manager.cpp
index e94d42a10..31b12546a 100644
--- a/src/core/border_router/routing_manager.cpp
+++ b/src/core/border_router/routing_manager.cpp
@@ -1752,6 +1752,18 @@ void RoutingManager::DiscoveredPrefixTable::HandleRouterTimer(void)
             continue;
         }
 
+        // If the `router` emitting RA has an address belonging to
+        // infra interface, it indicates that the RAs are from
+        // same device. In this case we skip performing NS probes.
+        // This addresses situation where platform may not be
+        // be able to receive and pass the NA message response
+        // from device itself.
+
+        if (Get<RoutingManager>().mInfraIf.HasAddress(router.mAddress))
+        {
+            continue;
+        }
+
         if (router.mTimeout <= now)
         {
             router.mNsProbeCount++;