A OpenWrt device, by default, always listens for SSH command line access on port 22. To “ssh into your router”, you enter the command ssh root@192.168.1.1 in a terminal emulator (for a router whose address is 192.168.1.1).

The first time you ssh into your router, you will probably see a warning about the RSA key fingerprint. If you are certain this is the address of your OpenWrt device, simply type yes and press Return. Then enter the password you have given to your router, or press Return if this is the initial setup. Here is an example session:

$ ssh root@192.168.1.1                                                    <== You type this
The authenticity of host '192.168.1.1 (192.168.1.1)' can't be established.
RSA key fingerprint is SHA256:4VbDA/MOc7inPiyllF5f0r3Q6iEx89ddKdhLGBovsiY.
Are you sure you want to continue connecting (yes/no)? yes                <== and this
Warning: Permanently added '192.168.1.1' (RSA) to the list of known hosts.
root@192.168.1.1's password:                                              <== and the password here

BusyBox v1.28.4 () built-in shell (ash)

  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 -----------------------------------------------------
 OpenWrt 18.06.2, r7676-cddd7b4c77
 -----------------------------------------------------

root@OpenWrt:~#                                                               <== type next command here

To end your ssh session to your router, type exit and press Return.

The remainder of this page describes several terminal emulators that Windows, Linux, or macOS can use to access your OpenWrt device.

Cmder, Smartty, Putty, and WinSCP are terminal emulators that allow you to ssh into a router.

As of April 2018, Win10 Powershell and command prompt provide SSH access after enabling the feature. Here's a description of the process: https://www.howtogeek.com/336775/how-to-enable-and-use-windows-10s-built-in-ssh-commands/

Cmder for Windows is an open-source terminal emulator that runs on Windows. It is free to use and provides an easy “command line shell” that allows you to ssh into OpenWrt. Its attractive fonts and color scheme are easy on the eyes. The Full distribution is preferred (over the mini distribution), since it provides a bash emulation, with a Unix-y suite of commands.

1. Download cmder from http://cmder.net/
2. Unzip the cmder.zip file
3. Open the Cmder folder, and double-click the Cmder icon. You'll see a Cmder window open similar to the image below.
4. To ssh into the OpenWrt router at 192.168.1.1, type ssh root@192.168.1.1 then press Return

Smartty gives you command line access to OpenWrt and allows you to open/edit/download/upload files in OpenWrt, and is overall more modern and user-friendly than Putty (another tool detailed below):

1. Download Smartty from http://smartty.sysprogs.com/: choose “download” for the installer, or “portable version” if you want it as a standalone program that works without installation.
2. after installation or after unzipping the archive, doubleclick on SmarTTY executable file.
3. You will be greeted by a window with two choices, doubleclick on “setup a new SSH connection” (the other option is for serial connections, for usb-TTL dongles and somesuch you connect to the device's debug serial pins on the board, we won't use that now).
4. The window changes into the SSH setup, write the following info:
   1. Host name: OpenWrt device IP address (default is 192.168.1.1 )
   2. User Name: root (this is the “administrator” and only user in default OpenWrt)
   3. Password: leave this blank for your first connection, then write the password you set up (either in Luci GUI or after your first SSH access)
5. Click “Connect” button at the bottom, and you will now see a big terminal screen coming up
6. A default OpenWrt firmware lacks the server component to allow you to open/edit/view/upoad/download files in Smartty, so after you have connected to the internet write opkg update && opkg install openssh-sftp-server to install it. If the next step fails, it might be necessary to reboot the OpenWrt device for this new service to start up properly.
7. Now you can click on File → Open a Remote File to open a popup that shows the filesystem of the OpenWrt device, and you can navigate in it and open text files for example as normal (they will open in a SmarTTY text editor window)
8. If you want to upload or download files to/from a specific folder in the device, you can click on SCP menu and choose the most appropriate action from there.

After the first time you connected to a device, Smartty saved a profile, so you can connect again to the same device (at that IP address with that password) by just doubleclicking its icon on the first window you see when starting Smartty. You can right-click on this profile icon to edit it again, if needed.

Putty gives you command line access to OpenWrt:

1. Download Putty from http://www.putty.org: Simply get the 32bit putty.exe download from the Alternative binary files section.
2. Start putty.exe on your Windows client → Putty's login window pops up.
3. go to the Session category of Putty's login window, look for the field Host Name (or IP address) and simply enter the IP-address (e.g. 192.168.1.1) of your OpenWrt device, keep the default provided port 22.
4. Click the Open button at the Bottom to open a connection. This will pop up a shell windows, asking to login as. Login as root with the OpenWrt password you have defined some time before. If you have not yet set a password yet on “root”, you will not be asked for the password.
5. Done, you are logged into the OpenWrt command line.

WinSCP allows you to browse the OpenWrt file system in Windows Exlorer like GUI-style:

1. Download WinSCP from https://winscp.net/eng/download.php, get the non-beta Installation package or portable executables and install or unzip them on your Windows client
2. Start WinSCP.exe on your Windows client, WinSCP's login window will pop up
3. Click on New Site on the left, then enter your OpenWrt device IP address (192.168.1.1) on the right side into Host name, keep the default port 22. In User name enter root, in Password, enter your root password (or leave blank, if you have not set a password yet)
4. Click the Login at the bottom of the Window.
5. Done. You now have an Exlorer-like view of your OpenWrt filesystem.

Editing OpenWrt config files with WINSCP's integrated GUI editor:
To edit a OpenWrt config file with WinSCP's GUI-based editor, just right-click the file in WinSCP and select Edit from the context menu.

All Linux distributions provide a command-line ssh client as part of the default installation.

1. Open a terminal emulator and write ssh root@192.168.1.1 (“ssh” is the command, “root” is the OpenWrt user you are connecting to, and “192.168.1.1” is OpenWrt default IP)
2. there will be a message about accepting a new key from the OpenWrt device, write “yes” and press Enter key.
   1. If for some reason you have reinstalled OpenWrt the device will have a different key and you get an error about key mismatch. The error will state what is the command line to copy-paste in your terminal to delete the old key and proceed.
3. if you want to close the session, write “exit”

Linux also usually has SCP clients (to open/edit/download/upload files in OpenWrt), which may or may not be installed by default. You need to look up your distro's documentation or search with your package management interface for “SCP” to find where it is and its current installation status. Read its integrated manual (“man scp” for example is for the command line SCP client) or google some tutorials to learn how to use it.

On macOS (formerly Mac OSX) any terminal emulator will allow you to ssh. There several terminal emulators:

1. Terminal - The macOS built-in terminal program. Find it in /Applications/Utilities
2. iTerm2 https://iterm2.com/ a much-enhanced terminal program. Donation-ware - it's worth it.

To ssh into your OpenWrt router at 192.168.1.1, type ssh root@192.168.1.1, then press Return.