diff --git a/.gitmodules b/.gitmodules
index 55ccddc..e55c450 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -2,3 +2,12 @@
 	path = zto
 	url = https://github.com/zerotier/ZeroTierOne.git
 	branch = dev
+[submodule "ext/lwip"]
+	path = ext/lwip
+	url = https://git.savannah.nongnu.org/git/lwip.git
+[submodule "ext/lwip-contrib"]
+	path = ext/lwip-contrib
+	url = https://git.savannah.nongnu.org/git/lwip/lwip-contrib.git
+[submodule "ext/ZeroTierOne"]
+	path = ext/ZeroTierOne
+	url = https://github.com/zerotier/ZeroTierOne.git
diff --git a/ext/ZeroTierOne b/ext/ZeroTierOne
new file mode 160000
index 0000000..d55c732
--- /dev/null
+++ b/ext/ZeroTierOne
@@ -0,0 +1 @@
+Subproject commit d55c732e1915affd2f40321261bb8178fa28f95a
diff --git a/ext/lwip b/ext/lwip
new file mode 160000
index 0000000..5bef7ea
--- /dev/null
+++ b/ext/lwip
@@ -0,0 +1 @@
+Subproject commit 5bef7ea72f4d4e36169966ba7de9068b1608e6a0
diff --git a/ext/lwip-contrib b/ext/lwip-contrib
new file mode 160000
index 0000000..2917f46
--- /dev/null
+++ b/ext/lwip-contrib
@@ -0,0 +1 @@
+Subproject commit 2917f46ded09ad83d2567171751df16c03366cbb