diff --git a/src/tools/hexnet.cpp b/src/tools/hexnet.cpp
index c7dcffc..751e26d 100644
--- a/src/tools/hexnet.cpp
+++ b/src/tools/hexnet.cpp
@@ -33,6 +33,7 @@ int main(int argc, char* argv[]){
     bool tcp = true;
     bool udp = true;
     bool server = false;
+    std::string host = "";
     uint16_t port;
     if (argc<2) {
         usage;
@@ -73,11 +74,13 @@ int main(int argc, char* argv[]){
             return EXIT_SUCCESS;
         }
         if (!server && i==argc-2) {
-            //TODO: check if valid host
-            std::cerr << "Host argument parsing is not yet implemented." << std::endl;
-            return EXIT_UNIMPLEMENTED;
+            host = argument;
         }
         if (i==argc-1) {
+            if (!server && host=="") {
+                std::cerr << "Not running in listen mode and no host specified." << std::endl;
+                return EXIT_USAGE;
+            }
             if (argument.substr(0, 2)=="0b" || argument.substr(0, 2)=="0B") {
                 // check for 16 bit binary number
                 for (char const &digit : argument.substr(2,argument.length())) {
@@ -136,5 +139,10 @@ int main(int argc, char* argv[]){
     }
     // Argument parsing end ############################################
 
-    //TODO: implement the actual tool
+    if (!server) {
+        //TODO: verify that host is possibly a valid host (or usage error)
+        //TODO: look up host if necessary, determine IPv4 or IPv6 mode if necessary
+        std::cerr << "Client mode not implemented" << std::endl;
+        return EXIT_UNIMPLEMENTED;
+    }
 }