Best way to setup a decent secured connection between my linux laptop and tx2 at a coffee shop

I’m going to this meetup group at a coffee shop next week and will be taking my tx2 with me. I will need an internet connection on my TX2 for the development work I’m wanting to accomplish there. Obviously, I guess I’ll use ssh for my remote session and will probably just use scp for moving files over from my laptop.

My understanding is that I can have my TX2 connect over wifi but I don’t know how to setup a static ip and would appreciate some instruction there. Otherwise, I have no idea how to find my dynamic ip of my tx2 from my laptop when connected to the coffee shops wifi. I guess I could nmap their network but rather not go through that ordeal. Ideally, in this method I would use a static ip to remote in over ssh using the coffee shops wifi.

Is there any other way to do this with a cross over Ethernet cable? I’ve ordered one yesterday and was hoping I could just hook up my tx2 to my laptop using this cross over and piggy back off my laptops wifi connection. I thought this would be more secure and a better setup in general but that is just a guess. Regardless, I have no idea how to set this up other than plug in the cross over cable.

What’s the most ideal way here that is easiest enough for a newb like myself to setup. If you could dumb it down and provide some methodical steps in setting the most ideal method up it would be much appreciated. Links are welcomed as well.

regnar86,

Seems you don’t have any way to connect TX2 to coffee shop wifi, right? Usually we use UART debugger to check ip when work, but I guess it is also not work for your case.

Then you should setup your TX2 as WIFI AP. Please prepare a monitor for this because we are going to setup through GUI.

1. Turn OFF Wi-Fi (Pre-requisite)
2. Connect ethernet cable to DUT to give it internet source
3. Turn ON wireless hotspot on DUT using GUI interface
(i) To allow SSID broadcasts, the following bcmdhd module paramter should be set: op_mode=2. Set this in two ways:
a) manually via /sys/module/bcmdhd/paramters/op_mode node, or
echo 2 > /sys/module/bcmdhd/parameters/op_mode
b) to set the parameter automatically on boot, add a bcmdhd.conf (module conf fine, the name may change) file to /etc/modprobe.d with this line:
options bcmdhd op_mode=2
(ii) Create a new connection in "Network Connection" settings using GUI
a) Click Network icon on GUI -> Edit-connections -> click "Add" button
b) Choose Wi-Fi from dropdown
c) In Edit window enter custom "Connection name", SSID, select device MAC address (primarliy of wla0)
d) Under WiFi-Security select WPA and WPA2 Personal and give a passcode
e) Under IPv4 Setting select "Shared to other computers"
f) In newly created system-connection file for your hotspot, change mode=ap
For e.g. sudo vim /etc/NetworkManager/system-connections/
# and set mode=ap in the given file
(iii) Turn ON Wi-Fi, to enable hotspot
(iv) Your hotspot is ready to use now
4. Connect other (client) device to this hotspot and access network using it

After these steps, you do not need to use monitor in coffee shop, wifi AP will be up automatically after device boots up.

Additional note: The “ubuntu” account is a default account with a known password. Never ever use this on any non-private network without changing the password first. The “nvidia” account is also a published known password…though not as many people know it, many do…so you’d need to change this password as well.

@WayneWWW

What do you mean my DUT? Device under test? I assume you mean TX2? Also I didn’t realize the TX2 had hot spot capability. Thank you both for the procedure and precautions. I’ll be going through that tonight at home and will definitely reach out if I run into any issues.

I have the hot spot up now on the TX2 and can ssh in (from my host “laptop”) after I connect to the hotspot. However, this doesn’t provide an internet connection to the outside where the TX1 can download data. This is a local intranet which is great for ssh but I also need my TX2 to be able to establish an internet connection.

Why do I need an internet connection for my TX2?
I’m developing with Rust on the TX2 and I need to download crates and other dependencies from the web. I also need to download other third party software. I can do this at home but was hoping there was a way to do this at the coffee shop.

In addressing your original question “Seems you don’t have any way to connect TX2 to coffee shop wifi, right?”…
I can connect to my coffee shops wifi using wireless on the TX2 but this obviously requires me to have a monitor to log in to tx1, select their network, enter password, etc. I don’t want to bring a monitor with me.

Furthermore, I have attempted something similar when I’ve worked with the beagle bone black. This link here shows how to do this over usb https://www.digikey.com/en/maker/blogs/how-to-connect-a-beaglebone-black-to-the-internet-using-usb/cdf66181b3a5436e9ad730e4ed4cf9ee. I’m guessing this doesn’t work on the tx2? Can I do something similar on the TX2?

You just need to set up your laptop as a router and on the Jetson point at the laptop as the gateway. I don’t know the details on Ubuntu, but if you find the right network setup tool, then it shouldn’t be too hard. Just be very sure your laptop, when acting as a hot spot, only acts as such for the MAC address of your Jetson.

In the above didn’t I set up my TX2 as the hot spot? I’m confused when you say “be sure your laptop, when acting as a hot spot…”. I didn’t realize my laptop was acting as the hot spot.

I lack WiFi experience, but if a hot spot implies it is a router as well, then you are set. You might want to connect your Jetson to the laptop, and then run “ifconfig” on each and post what it says…plus perhaps the command “route”.

If you use laptop as wifi hotspot, you can set TX2 auto-connect to it, so that you don’t need to use monitor or anything else when your are outside.

To find the IP address, DHCP tends to assign IP in increasing order… maybe you can try to guess it or just check if laptop has client info or not.

Solution 1:

  1. Take a lite wifi AP as “Amplifier” in shop. Before you go, make sure your laptop and TX2 can automatically connected to your small AP.
  2. When you runs into the shop, setup your AP work in RELAY mode or AMPLIFIER mode.
  3. Setup your internet connection from your laptop through your lite AP and the shop’s public AP.

Solution 2:

  1. Use cable directly make TX2 connected to your laptop.
  2. Add a sub-IP associate your laptop’s network card to communicate with TX2 (TX2 need a static IP under same sub-network with your laptop sub-IP network.)
  3. Use your laptop’s wifi connecting to shop’s public AP.

Solution 3. (need details)

  1. Use network tools (wireshark…sth) from laptop to catch IP packages. (Use TX2 wifi mac as target.)
  2. Setup TX2 wifi connection (iwconfig) from laptop