Hi Ken, Thank you for your help. I am indeed using localhost in both cases. I am able to ping localhost even when disconnected. Thanks! Alexis Cheng Electrical Engineering University of British Columbia Hi Alexis, Personally, I'm stumped. This doesn't appear to be just a ROS network configuration issue. For some reason, your machine appears to be unable to resolve localhost, which should work even when you're not connected. I'm not aware of any reason why your ROS should work when you are plugged in versus unplugged, if in both cases you are using 'localhost'. Is it the case that you can ping localhost even when you're not connected? - Ken On Mon, May 10, 2010 at 3:20 PM, Alexis Cheng wrote: Hi Ken, I changed ROS_IP to 127.0.0.1, but the problem is persisting. Are there any steps/procedures to ensure the proper network configuration for ROS besides those outlined in the wiki? Thanks! Alexis Cheng Electrical Engineering University of British Columbia Hi Alexis, For some reason 'localhost' isn't resolving on your machine. I would recommend trying using ROS_IP=127.0.0.1 instead of ROS_HOSTNAME=localhost. NOTE: this will disable your ability to connect to remote machines with ROS. - Ken On Mon, May 10, 2010 at 3:09 PM, Alexis Cheng wrote: Hi all, I have installed ROS on a single Ubuntu machine and it seems to be working while connected to the internet. However, roscore is unable to run without internet connection. Roswtf does not return any errors or warnings. ----- Roscore responds with: [ERROR] 1273528178.429037000: [registerService] Failed to contact master at [localhost:11311]. Retrying... Rosrun responds with: Couldn't find an AF_INET address for [localhost] [ERROR] 1273528740.753778000: [registerPublisher] Failed to contact master at [localhost:11311]. Retrying... ----- I have went through the network setup document on ROS wiki and it seems to pass the tests. I have also changed ROS_HOSTNAME to localhost. Has anyone encountered this problem before and managed to correct it? Thanks! Alexis Cheng Electrical Engineering University of British Columbia 30 days of prizes: Hotmail makes your day easier! Enter now _______________________________________________ ros-users mailing list ros-users@code.ros.org https://code.ros.org/mailman/listinfo/ros-users Win a $10,000 shopping spree from Hotmail! Enter now Enter now _______________________________________________ ros-users mailing list ros-users@code.ros.org https://code.ros.org/mailman/listinfo/ros-users _________________________________________________________________ Win a $10,000 shopping spree from Hotmail! Enter now. http://go.microsoft.com/?linkid=9729711