[Fred Kemmerer]

Hello Emily,

AREDN does support communication with HaLow devices. Can you tell us a little bit about the devices that you are interested in? Here are a few links with some information on AREDN HaLow support –

https://docs.arednmesh.org/en/latest/arednNetworkDesign/frequency_bands.html#mhz-characteristics

https://www.arednmesh.org/content/aredn-release-325100-80211ah-support

 

 

[Fred Kemmerer]

Hi Dave,

AREDN uses 10.x.x.x and 172.x.x.x addresses for the local mesh. It is best to configure your home network to use 192.168.x.x addresses to avoid conflicts with the AREDN addresses.

I believe it may be possible to continue using 10.x addressing on your home network; this would require several static routes and would leave you vulnerable to future addressing conflicts with AREDN.

[Fred Kemmerer]

Just heard from Dave Pascoe, Km3T, who is doing the install at KC1XX –

Too cold and windy. Monday is possible, we will make a call on Sunday night.

We will not be installing the AREDN RF link tomorrow. This is a good call as it’s not safe to be on towers when the wind and cold are a problem.

I will let everyone know by posting here on Sunday evening whether the installation is a go for Monday.

[Fred Kemmerer]

ARRL Members can vote for Frank’s excellent article here –

https://www.arrl.org/cover-plaque-poll

Nice job, Frank!

[Fred Kemmerer]

Thank you, Hamilton!

[Fred Kemmerer]

Thanks Bill. I will be having another contact with a school in Canada on Tuesday. This ISS contact is scheduled to begin at 9:31 a.m. ET. We will post more information about this contact shortly,

 

Fred, AB1OC

[Fred Kemmerer]

FB Brian, count me in.

Fred AB1OC

[Fred Kemmerer]

The Public key mentioned above is generated randomly as part of the SSH key pair creation process. You can learn more about generating SSH key pairs here –

https://www.ssh.com/academy/ssh/keygen

When we first set up Linux on on RPi, we generated an SSH key pair. Later, we changed the SSH key to use a different pair that I generated on my macOS system. This caused the fingerprint for the server to change and I had to edit .ssh/known_hosts to remove the old fingerprint so a new one could be generated.

Fred, AB1OC

[Fred Kemmerer]

Here is a little more about how the SSH fingerprint is generated –

The fingerprint is based on the host’s public key, usually based on the /etc/ssh/ssh_host_rsa_key.pub file.  Generally, it’s for easy identification/verification of the host you are connecting to.

You can view the contents of the file by running cat /etc/ssh/ssh_host_rsa_key.pub . To view that public key in fingerprint format, run ssh-keygen -lvf /etc/ssh/ssh_host_rsa_key.pub.

If the fingerprint changes, the machine you are connecting to has changed their public key. This may not be a bad thing (happens from re-installing ssh), but it could also indicate that you are connecting to a different machine at the same domain/IP (happens when you are connecting through something like a load balancer) or that you are being targeted with a man-in-the-middle attack, where the attacker is somehow intercepting/rerouting your ssh connection to connect to a different host which could be snooping your username/password.

Bottom line: if you get warned of a changed fingerprint, be cautious and double-check that you’re actually connecting to the correct host over a secure connection. Though most of the time this is harmless, it can be an indication of a potential issue.

[Fred Kemmerer]

Hi Dave,

Got it. What we are doing at this point in the setup video is making the initial connection between our Home Server and our PC. The connection is encrypted using SSH (the command we are running to make the connection).

The first time we access our Raspberry Pi from our PC, a unique fingerprint is generated which identifies the specific hardware device our server is running on. Subsequent connections from our PC to the Pi will confirm that the same fingerprint is supplied each time we connect.

If a hacker were to get onto our network and try to emulate our server, their device would not be able to generate the correct fingerprint and our PC would refuse to connect via SSH.

Some SW updates can sometimes cause this fingerprint to change. If this happens, you can edit a file on your PC in your home directory called .ssh/known_hosts to remove the recorded fingerprint for your server and set a new one.

You can learn more about SSH and fingerprints here –

https://www.jscape.com/blog/ssh-key-fingerprint

Fred, AB1OC

[Author]

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