diff --git a/_vm/common.yml b/_vm/common.yml
new file mode 100644
index 0000000..52b5689
--- /dev/null
+++ b/_vm/common.yml
@@ -0,0 +1,20 @@
+version: "3.0"
+
+#
+# updated: 2023-12-10
+# stack:   x-common
+#
+
+services:
+
+  x-common:
+
+    extends:
+      file: ./host.yml
+      service: x-host
+
+    init: true
+
+    sysctls:
+      net.core.somaxconn: 1024
+      net.ipv4.tcp_syncookies: 0