diff --git a/data.h b/data.h
index 6d89822..b669ac3 100644
--- a/data.h
+++ b/data.h
@@ -7,8 +7,18 @@
 #pragma once
 
 #include <cstdint>
+#include <arpa/inet.h>
 
 typedef uint8_t u8;
 typedef uint16_t u16;
 typedef uint32_t u32;
+typedef uint64_t u64;
+
+typedef struct sockaddr_in6 SockAddr;
+
+struct Neighbour {
+	Neighbour(u64 id, const SockAddr& addr) : id(id), addr(addr) {}
+	u64 id;
+	SockAddr addr;
+};
 
diff --git a/nw_constants.h b/nw_constants.h
index 5c4cf2b..27bfe01 100644
--- a/nw_constants.h
+++ b/nw_constants.h
@@ -29,5 +29,7 @@ const int TIMEOUT_UNIDIR =		100*1000; // ms
 const int TIMEOUT_SYM_RECV =	150*1000; // ms
 const int TIMEOUT_SYM_IHU =		300*1000; // ms
 
-};
+const u16 DEFAULT_PORT = 1192;
+
+}