// === FUNCTIONS ===
extern int IPv4_RegisterCallback(int ID, tIPCallback Callback);
extern Uint16 IPv4_Checksum(const void *Buf, size_t Length);
+extern Uint32 IPv4_Netmask(int FixedBits);
extern int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int Length, const void *Data);
#endif