diff --git a/lwip b/lwip
index 51d48fe0c..c21d911aa 160000
--- a/lwip
+++ b/lwip
@@ -1 +1 @@
-Subproject commit 51d48fe0c67131da346c9ef280b2019c77f6e607
+Subproject commit c21d911aa4f178563dc102f595d1d97dd8471458