Hi, This is a simple question but troubled me hours.

I am following the turtlebot3 tutorial. Setting up the bashrc of host-pc with PC IP address 192.168.48.132 :

export ROS_MASTER_URI=http://**192.168.48.132**:11311
export ROS_HOSTNAME=**192.168.48.132**

Setting up the bashrc of turtlebot3 with its own IP 192.168.137.192 :

export ROS_MASTER_URI=http://**192.168.48.132**:11311
export ROS_HOSTNAME=**192.168.137.192**

Then, run the roscore on remote PC with the printout like this:

Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://192.168.48.132:38089/
ros_comm version 1.12.14

SUMMARY

PARAMETERS
 * /rosdistro: kinetic
 * /rosversion: 1.12.14

NODES

auto-starting new master
process[master]: started with pid [2167]
ROS_MASTER_URI=http://192.168.48.132:11311/

setting /run_id to ee0e1f5e-41df-11ea-8d67-000c29f89067
process[rosout-1]: started with pid [2180]
started core service [/rosout]

then run

roslaunch turtlebot3_bringup turtlebot3_robot.launch on turtlebot3

get 'unable to contact ROS master at [http://192.168.48.132:11311/]'

the bashrc setting ip is the same but why the turtlebot cannot find the ros master?

Thank you