Velodyne VLP-16 needing internet connection for sample_lidar_replay

The only way I can get the sample_lidar_replay to run live with my velodyne VLP-16 lidar is if I first connect my px2 platform to the internet via an ethernet cable. Then, I can remove that cable and then I can run the sample_lidar_replay successfully. If I do not do that step then it will not connect to the velodyne IP address and port. Can anyone help me on how to get connect without the internet? I think it may have to do with a timestamp issue but I’m not sure.

I was able to figure this out.

First, you need to change the Host(Destination) IP address in the velodyne configuration to a 192.168.1.XX , where XX is any number (different than the lidar’s own IP address).

Next, you need to go into the network settings of the Drive PX2, by going to “/etc/systemd/network/”. Next remove eth0 information from the existing network file (this is the [match] info and the DCHP info corresponding to eth0). Then create a new file, I called it static.network. In here, enter the following:

[Match]
Name=eth0

[Network]
Address=192.168.1.XX
Gateway=192.168.1.1
DNS=192.168.1.1

This keeps the Gateway consistent with the Lidar gateway. Now you have to restart your network settings by typing: “sudo systemctl restart systemd-networkd”

Then you can check to make sure its sending from lidar IP address and port, to px2 ip address and port by entering the command: “sudo tcpdump -i eth0”.

Now the sample_lidar_replay should be working with the following command:
“sudo ./sample_lidar_replay --protocol=lidar.socket --params=device=VELO_VLP16,ip=192.168.1.201,port=2368,scan-frequency=10,protocol=udp”