Transferring file from raspberry pi to PC

I've discovered many tutorials come up short because they fail to define the environment the test was run. When the environment changes so may the test.

It appears the Pi cannot translate the hostname of your desktop to the required IP address.

Try this test from the Pi

ping <hostname of desktop>

Do you get a response? Let's assume not and work on solution.

try adding .local to the desktop hostname.

<hostname of desktop>.local keeping the command the same except for that change.

This adds dynamic DNS to find the IP address of the hostname of the desktop

ALternate solution

Do you know the IP of your desktop?

Replace the <hostname of desktop> with the IP address, keeping the command the same except for that change.

I've discovered many tutorials come up short because they fail to define the environment the test was run. When the environment changes so may the test.

It appears the Pi cannot translate the hostname of your desktop to the required IP address.

Try this test from the Pi

ping <hostname of desktop>

Do you get a response? Let's assume not and work on solution.

try adding .local to the desktop hostname.

<hostname of desktop>.local keeping the command the same except for that change.

This adds dynamic DNS to find the IP address of the hostname of the desktop

ALternate solution

Do you know the IP of your desktop?

Replace the <hostname of desktop> with the IP address, keeping the command the same except for that change.

I assume by the yellow header you have been successful. Please don't assume it works everywhere but the chances that it will are improving.

The DDNS (dynamic domain name service) is a fairly new protocol. New in the sense more devices are supporting it. DNS translates URL to IP Addresses for the networks across the whole world. DDNS does the same translation for your little part of the world networks, provided one of the active devices in the network supports it.

It is best practice or a good idea to be familiar with using IP's to perform communication tasks. Using the IP removes the need for any overhead services that might contribute to the problem.

I would also suggest if this is your first foray into ssh (scp is the copy program within the suite) you locate the file /home/<username>/.ssh/known_hosts file. When two host make a connection the initiating hosts stores a hash in this file to identify the hosts it has connected with. You can see this happen on the first connection because you get asked a yes or no question. The next time it makes a connection the host compares what it has with what it receives on the connection. If different it will throw an error and not connect.

Let says for some reason you reload the Operating system on a host. It will send a different hash for a connections. The problem appears often (for me) because I rebuild Pi O/S's a far bit when I am working on a project. I call it flushing the known_hosts file so I don't get the error.

At one point in the ssh protocols life cycle you could look at the contents of known_hosts. For security reason much of the content is now encrypted so all you see now is formatted data. What it is you can't tell.