[mle] do not clear address query cache when switching to the router role (#2529)
diff --git a/src/core/thread/mle_router.cpp b/src/core/thread/mle_router.cpp
index 8f57f1f..66a9f8e 100644
--- a/src/core/thread/mle_router.cpp
+++ b/src/core/thread/mle_router.cpp
@@ -441,7 +441,6 @@
netif.GetIp6().SetForwardingEnabled(true);
netif.GetIp6().GetMpl().SetTimerExpirations(kMplRouterDataMessageTimerExpirations);
netif.GetMac().SetBeaconEnabled(true);
- netif.GetAddressResolver().Clear();
// clear router table
for (int i = 0; i <= kMaxRouterId; i++)