Hi I get some odd messages when I use roscore, how can I rectify them ? though, rosnode list and turtlesim works just fine ! Please help ! This is what I get ! ..... acer@acer:~$ roscore ... logging to /home/acer/.ros/log/85cd288c-93ce-11df-8359-001b777e0253/roslaunch-acer-3735.log started roslaunch server http://acer:41521/ SUMMARY ======== NODES WARNING: IP address 127.0.1.1 for local hostname 'acer' does not appear to match any local IP address (127.0.0.1,172.16.63.119,172.16.246.1,192.168.183.1). Your ROS nodes may fail to communicate. Please use ROS_IP to set the correct IP address to use. starting new master (master configured for auto start) process[master]: started with pid [3748] ROS_MASTER_URI=http://acer:11311/ setting /run_id to 85cd288c-93ce-11df-8359-001b777e0253 process[rosout-1]: started with pid [3759]