some documentation

1 files changed, 10 insertions, 1 deletions

diff --git a/src/anytun.cpp b/src/anytun.cpp
index d8f2159..50f2437 100644
--- a/src/anytun.cpp
+++ b/src/anytun.cpp
@@ -425,7 +425,16 @@ int main(int argc, char* argv[])
 			NetworkPrefix prefix( addr, rit->prefix_length );
 			gRoutingTable.addRoute( prefix, gOpt.getMux() );
 		}
-
+		if (connect_to.begin() == connect_to.end() && routes.begin() == routes.end() && gOpt.getDevType()=="tun")
+		{
+			std::cout << "No Routes and no syncronisation hosts have be specified"<< std::endl;
+			std::cout << "anytun won't be able to send any data"<< std::endl;
+			std::cout << "most likely you want to add --route 0.0.0.0/0 --route ::/0"<< std::endl;
+			std::cout << "to your command line to allow both ipv4 and ipv6 traffic"<< std::endl;
+			std::cout << "(this does not set operation system routes, use the post-up script"<< std::endl;
+			std::cout << " to set them)"<< std::endl;
+			return -1;
+		}
 #ifndef NODAEMON
     if(gOpt.getChroot())
       chrootAndDrop(gOpt.getChrootDir(), gOpt.getUsername());