diff --git a/dc/topo/proto/.gitignore b/dc/topo/proto/.gitignore
new file mode 100644
index 0000000..5608690
--- /dev/null
+++ b/dc/topo/proto/.gitignore
@@ -0,0 +1 @@
+config.pb.go
diff --git a/dc/topo/proto/BUILD.bazel b/dc/topo/proto/BUILD.bazel
new file mode 100644
index 0000000..3caae5b
--- /dev/null
+++ b/dc/topo/proto/BUILD.bazel
@@ -0,0 +1,22 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
+
+proto_library(
+    name = "proto_proto",
+    srcs = ["topo.proto"],
+    visibility = ["//visibility:public"],
+)
+
+go_proto_library(
+    name = "proto_go_proto",
+    importpath = "code.hackerspace.pl/hscloud/dc/topo/proto",
+    proto = ":proto_proto",
+    visibility = ["//visibility:public"],
+)
+
+go_library(
+    name = "go_default_library",
+    embed = [":proto_go_proto"],
+    importpath = "code.hackerspace.pl/hscloud/dc/topo/proto",
+    visibility = ["//visibility:public"],
+)
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;
+};