When should roscors's ros_master_uri not just be localhost?
On the computer running roscore, I understand that this is almost always sufficient.
export ROS_MASTER_URI=http://localhost:11311
Under what special circumstances does that computer need a specific IP address of ROS_MASTER? And does it ever need ROS_IP or ROS_HOSTNAME? My reasoning is that MASTER_URI points to roscore, which is itself, so localhost should always be good enough. I can't think of other scenarios, but they probably do exist!
Are you asking if there are conditions when you should use an IP address in
ROS_MASTER_URIinstead of a hostname? (E.g.,export ROS_MASTER_URI=http://192.168.0.0:11311instead ofexport ROS_MASTER_URI=http://myrobot:11311.)Note specifically I am talking about the computer running Roscore. My reasoning is that MASTER_URI points to roscore, which is itself, so localhost should always be good enough. I can't think of other scenarios, but they probably do exist!