diff --git a/network_manager.hpp b/network_manager.hpp
index 3d745ce..f37544c 100644
--- a/network_manager.hpp
+++ b/network_manager.hpp
@@ -29,7 +29,8 @@
 
 using IntfName = std::string;
 
-struct AddrInfo {
+struct AddrInfo
+{
     short addrType;
     std::string ipaddress;
 };
@@ -78,6 +79,9 @@
          */
         IntfAddrMap getInterfaceAddrs() const;
 
+        /** @brief converts the given subnet into prefix notation **/
+        uint8_t toCidr(const char* subnetMask) const;
+
         /** @brief Persistent map of EthernetInterface dbus objects and their names */
         std::map<IntfName, std::unique_ptr<EthernetInterface>> interfaces;