- SSH (Secure Shell)
- Provides an Interactive Login Shell
- Provide Non-interactive Remote Command Execution.
- Secure Network File Copy.
- Simple network tunnelling of traffic.
- Linux, MacOS and Unix all come with SSH Servers built-in.
- Windows does not come with SSH.
- In Linux, the main configuration files are stored in
/etc/ssh
- The client has these stored in
/etc/ssh/ssh_config
- The server has these stored in
/etc/ssh/sshd_config (this is the main one, only really need to edit this one) and /etc/sysconfig/sshd
- SSH answers on port 22 by default, but can change this in the file.
- Many other items in the file, such as ciphers, compression, access control and forwarding.
- Per user client configuration file.
~/.ssh/config
- Helps for overwriting certain configuration items.
- The
.ssh directory does not exist, until you attempt to connect to a server for the first time.
- Helps stores information about the remote service.
- Example of a user’s personal configuration:
- If a remote server uses port
1022 and a private-public key is generated for it, the above image configuration file would look like that.
- If there was no configuration file, we would hae to type in the command like so:
ssh -p 1022 howard@server1.vmguests.com -i ~/.ssh/server1.key
-i is used for the identity of the file.
- WIth the above config file in place, all we need to do is type in
ssh server_name
- Makes management and access to multiple servers easier.