You can configure your SSH client to automatically add your key when making an SSH connection.
nano ~/.ssh/config
Host *
AddKeysToAgent yes
IdentityFile ~/.ssh/id_rsa
Again, replace ~/.ssh/id_rsa with the path to your SSH key if necessary.
This will automatically add your SSH key to the agent whenever you initiate an SSH connection.
nano /etc/ssh/sshd_config
PermitRootLogin prohibit-password PasswordAuthentication no PubkeyAuthentication yes
systemctl restart sshd
Add your public key to the authorized keys file on remote server. To add you keys to the file, you can use the following command:
cat ~/id_rsa.pub >> ~/.ssh/authorized_keys
If you do not have the folder ~/.ssh/authorized_keys , you can create this with the following commands:
mkdir -p ~/.ssh touch ~/.ssh/authorized_keys
References
https://medium.com/@williamkwao/how-to-add-ssh-keys-to-an-ubuntu-server-6a3a5b1bee26
sudo apt install fail2ban -y
sudo systemctl enable fail2ban sudo systemctl start fail2ban
sudo systemctl status fail2ban
Configuring Fail2ban
sudo cp /etc/fail2ban/jail.conf /etc/fail2ban/jail. Local
sudo nano /etc/fail2ban/jail. Local
References
https://www.howtoforge.com/how-to-install-fail2ban-on-ubuntu-22-04/
Error while using port forwarding on SSH : Cannot assign requested address
You can force the use of IPv4 on the commandline with the -4 switch:
ssh -4 -L 8080:127.0.0.1:80 dev.local
References
https://www.electricmonk.nl/log/2014/09/24/ssh-port-forwarding-bind-cannot-assign-requested-address/
https://www.putorius.net/force-ssh-client-to-use-ipv4-or-ipv6.html
# Keys need to be only readable chmod 400 ~/.ssh/id_rsa
Keys need to be read-writable chmod 600 ~/.ssh/id_rsa
References
https://stackoverflow.com/questions/9270734/ssh-permissions-are-too-open-error
localhosthost1 is accessible to localhosthost2 only accepts connections from host1localhost to host2You basically have three possibilities:
localhost to host1:
ssh -L 9999:host2:1234 -N host1
As noted above, the connection from host1 to host2 will not be secured.
localhost to host1 and from host1 to host2:
ssh -L 9999:localhost:9999 host1 ssh -L 9999:localhost:1234 -N host2
This will open a tunnel from localhost to host1 and another tunnel from host1 to host2. However the port 9999 to host2:1234 can be used by anyone on host1. This may or may not be a problem.
localhost to host1 and from localhost to host2:
ssh -L 9998:host2:22 -N host1
ssh -L 9999:localhost:1234 -N -p 9998 localhost
This will open a tunnel from localhost to host1 through which the SSH service on host2 can be used. Then a second tunnel is opened from localhost to host2 through the first tunnel.
Normally, I’d go with option 1. If the connection from host1 to host2 needs to be secured, go with option 2. Option 3 is mainly useful to access a service on host2 that is only reachable from host2 itself.
References
https://superuser.com/questions/96489/an-ssh-tunnel-via-multiple-hops
Start adb daemon on remote device
adb devices
$ adb devices * daemon not running. starting it now on port 5037 * * daemon started successfully * List of devices attached 5200fe4259bcc000 device
do client to server port forwarding using ssh on port 5037
References
https://dontbelievethebyte.github.io/articles/2015/01/15/debug-remotely-on-android-via-ssh-tunnel/
https://developer.android.com/studio/command-line/adb
https://stackoverflow.com/questions/2604727/how-can-i-connect-to-android-with-adb-over-tcp
scp <source> <destination>
To copy a file from B to A while logged into B:
scp /path/to/file username@a:/path/to/destination
To copy a file from B to A while logged into A:
scp username@b:/path/to/file /path/to/destination
rsync -avz -e 'ssh -p 22002' /root/backup/monitoring_201909280430 [email protected]:/root/backup/