diff --git a/dc/topo/proto/topo.proto b/dc/topo/proto/topo.proto
new file mode 100644
index 0000000..0127bf8
--- /dev/null
+++ b/dc/topo/proto/topo.proto
@@ -0,0 +1,35 @@
+syntax = "proto3";
+
+package topo;
+option go_package = "code.hackerspace.pl/hscloud/dc/topo/proto";
+
+message Config {
+    repeated Switch switch = 1;
+    repeated Machine machine = 2;
+};
+
+message Switch {
+    string name = 1;
+    string control_address = 2;
+    message SwitchPort {
+        string name = 1;
+    };
+    repeated SwitchPort managed_port = 3;
+    message Segment {
+        enum Type {
+            TYPE_INVALID = 0;
+            TYPE_VLAN = 1;
+        }
+        Type segment_type = 1;
+        int32 vlan_id = 2;
+    };
+    repeated Segment available_segment = 4;
+};
+
+message Machine {
+    string name = 1;
+    message Port {
+        string name = 1;
+    };
+    repeated Port managed_port = 2;
+};