i have logged into my laptop on my laptop and desktop on my desktop, when i try to log on to ssh coop@10.x.x.xx i get this

i have however succesfully ssh from my desktop to my laptop!

As the warning states run the command.
ssh-keygen -f "/home/cooper/.ssh/known_hosts" -R 10.0.0.24

Let me know when you created the keys and tested the keys

got it! i have ssh on my laptop to desktop and vice versa!!!! thank ya I couldn't have done that myself! btw how do you get updated so quickly that I made a post

Using keys?

I did the keygen and passphrase thingy if that is what ya mean?

for ex I am on my laptop. I ssh into my desktop. within the desktop I keygen then saved it to my desktop set my passphrase and then had to logout twice

Ok. Now go back and disable password authentication.

You should still be able to login.

To access the desktop from outside your network requires some additional steps.

You need to log into the router and add an address reservation for the desktop. You also need to configure the router to forward port 22 to the desktop IP address.

You should be able to login to the desktop using your public IP address. You can find your public IP address from the WAN setup page in your router or whatsmyipaddress.com or similar web site.

ssh user@public_IP_address.

okay, say i want to add my phone, do i add a key or if im not really worried about it can i just let it be? cause when i went to use the keygen command it wanted to overwrite the file which i said no to. If I hit yes would it keep the old keys?

by the way that video I was watching online, the guy was on /etc/ssh/sshd_config as opposed to /etc/ssh_config do I have to change the password authentication on that doc as well? cause when I turned it off, O restarted the service it was permission denied (publickey) so I turned it back on for the time being.

sshd_config is the server file and ssh_config the client. No you do not need to change ssh_config.

Do you want to run a ssh server on your phone or log into your desktop? It depends on the phone and what application needs to be installed.

I have the terminus app on my iPhone (don’t shoot) so I can log in and I have ssh into both devices. I just don’t have any keys set up and your help has been superb by the way

I don't know. I am not familiar with the app but I think so.

They also run a terminal emulator nothing real special though

The best way is to add a key to the phone, but you can generate the key anywhere and then transfer the private half to the phone and the public half to the target machine.

It's usually considered a good idea have a unique key pair for each set of devices. So the phone should be using its own keys to connect to either the desktop or the laptop.

You can use the -f option to name the key file someting unique. That way the old file won't get overwritten. Likewise you can add the -C option to add a note to help remember what the key is for.

Note that you can use "-t ed25519" instead of "-t rsa -b 4096" if you can handle modern keys, which would make keys using the Ed25519 algorithn. The phone might not handle those, so the above makes 4096-bit RSA for the phone just in case backward compatibility is needed. However, check with the documentation for Termius and see if it supports Ed25519 and use that instead if you can. It's not just a new algorithm, it's in a different category from RSA.

Then put the keys in place:

Then on each client you can see your key files in the directory ~/.ssh/ and on each "server" in the file ~/.ssh/authorized_keys You can use the file ~/.ssh/config in each of the client machines to make shortcuts. So on the laptop you'd have:

Then you'd only need to type "ssh desktop" on your laptop and it will connect. If you like that, do vice versa for the desktop's ssh_config file.

Somehow you will have to get "ph_to_laptop" and "ph_to_desktop" over to the phone. You write that you have an iPhone, the Termius app on the iphone has a lot fewer features than the Android version. It says "PuTTY" keys on the Apple page so you may have to convert the phone's keys before transferring them to the phone.

Ah I see, thank you for the explanation Turbo!