Comment by spiritninja for Make sure you have set in navfn_global_planner_params.yaml:allow_unknown: false #Specifies whether or not to allow navfn to create plans that traverse unknown space, default true I have observed that sometimes the first plan (after setting a goal) can still be wrong, but then it gets updated by the next plan (which is correct). If the planner frequency is high enough, then the robot does not have a chance to do anything undesirable.Also, from:https://answers.ros.org/question/2155...Are you using a layered costmap from costmap_2d with an obstacle or voxel layer? If so you have to set the param track_unknown_space for that layer to true, otherwise it's converting your map's unknown space into free space (which navfn then correctly goes quite happily through).So, make sure you have also set in costmap_common_params.yaml: track_unknown_space: true #true needed for disabling global path planning through unknown space

Exactly. This is what I was trying out the other day after checking about the global planner [Here](http://wiki.ros.org/global_planner) on the Wiki page. https://answers.ros.org/question/198255/set-unknown_cost_value-in-costmap/ The above discussion is the one I was referring. The robot `costmap_common_params.yaml` is as follows obstacle range: 2.5 raytrace_range: 3.0 footprint: [[0.35, -0.3], [0.35, 0.3], [-0.35, 0.3], [-0.35, 0.3]] inflation_raduis: 0.05 obstacle_layer: observation_sources: hokuyo_laser hokuyo_laser: {sensor_frame: hokuyo_laser_link, data_type: LaserScan, topic: /hokuyo_base/scan, marking: true, clearing: true} So, as the `track_unknown_space` parameter wasn't present earlier, i thought adding it under the `obstacle layer` would suffice. But it didn't change anything. @jordan any suggestion on this? I appreciate the help provided.