Setting this option to 'yes' in the global client configuration file /etc/ssh/sshconfig enables the use of the helper program ssh-keysign(8) during HostbasedAuthentication. The argument must be 'yes' or 'no'. The default is 'no'. This option should be placed in the non-hostspecific section. See ssh-keysign(8) for more information. Go on server and create two users user1 and user2. Open main configuration file sshdconfig. Check the value of PasswordAuthentication directive. In order to accept local user password base authentication it must be set to yes.Set it to yes if it is set to no and save the file. Restart the service if you have made any change in sshdconfig. Go on linuxclient system and verify that both users. Sample SSH Config File Example. Now I can just do SSH for one of these servers and the respective configuration option will be used for the connection (Here I have not defined any server1 in /etc/hosts and this mapping is working due to the SSH configuration file) deepak@client $ ssh server1 root@ 192.168.43.154 's password: Welcome to server1 This file was created on 2020-02-01 Go away if. If you don't have an SSH key pair, open a bash shell or the command line and type in: ssh-keygen -t rsa -b 2048 This will generate the SSH key. Press Enter at the following prompt to save the key in the default location (under your user directory as a folder named.ssh).
I am trying to modify ssh for more secure setting according to this article which says
SSH Settings
While the SSH daemon is secure enough for most people, some may wish to further enhance their security by changing certain sshd settings. Some settings which could be changed to enhance security are given here. All changes, unless otherwise stated, are made in the /etc/ssh/sshd_config file. Lines with a pound sign (#) are commented and not read. To edit this file from a terminal:
sudoedit /etc/ssh/sshd_config
When I go to edit the file, the path on my ubuntu 9.10 install is /etc/ssh/ssh_config instead of sshd_config.
Is this ssh installed and running by default on ubuntu 9.10? Need I worry about it?
Enable UDM SSH Access
If you don’t have remote access enabled, you will need to be connected locally to the UDM, and navigate to it’s IP address in a web browser.
If you have remote access enabled, you can navigate to unifi.ui.com and access the SSH setting there.
Enable SSH in the UDM Device settings:
Click on the gear icon to access the UDM device settings
Click on Advanced
Enable SSH and set your SSH password
SSH into the UDM with the username of “root” and the password you just set
Open your terminal application of choice. There are many applications that you can use, but some quick recommendations based on your OS:
macOS = built-in Terminal application. I also like Termius.
Windows = PuTTY, or enable the new built-in Windows Terminal in Windows 10.
Linux = You should already know this! Case for mac pro retina 15.
If your IP address is 192.168.1.1, you’d type ssh root@192.168.1.1 and hit enter. Replace the IP, but the username is always root.
If this is your first time accessing the device, accept the authenticity of the host key by typing yes and hit enter
Access the UniFi OS shell by typing unifi-os shell and hit enter
What You Can Do With SSH Access
If you’re not familar with SSH, Ubiquiti has a good help page which introduces what SSH is and how it works. The one sentence summary is that SSH allows for a safe way to read and write the configuration, access logs, and troubleshoot problems.
The “configuration” part doesn’t really apply to the UDM, though. With the UDM, you have to make your permanent configuration changes through the web UI. The UDM doesn’t have a configuration shell, you will only have direct Linux shell access. The Unifi service or a firmware update will overwrite most things you can change.
UbiOS/UniFi OS is based on Buildroot Linux, and is Ubiquiti’s custom implementation. You are not allowed to install packages or modify things like you might be used to on other Linux-based devices. With that said, there’s still a few things you can do.
Available commands
Typing “help” shows an incomplete list of the commands that are available:
Built-in commands available to root user:
. : [ [[ alias bg break cd chdir
command continue echo eval exec
exit export false fg getopts
hash help history jobs kill let
local printf pwd read readonly
return set shift source test times
trap true type ulimit umask
unalias unset wait
Standard Linux commands like ifconfig, tcpdump, netstat, whoami and cat are also available. There are also some commands and files that are unique to the UDM and not well documented by Ubiquiti. This reddit thread shows a good list of these unique commands, file locations, and what they are good for. Refer to the commands on the right side of the table
Retrieve Log Files
This is Ubiquiti's help article for how to retrieve log files. You can use view the specific logs you’re interested in by using the cat command, or view live logs with tail.
Show UniFi server logs with: cat /mnt/data/unifi-os/unifi/logs/server.log
Show UniFi system logs with: cat /mnt/data/unifi-os/unifi-core/logs/system.log
Refer to Ubiquiti’s help page and this Reddit thread for more examples.
Manual Firmware Upgrade
One of the most common uses of SSH is firmware upgrades, especially for beta firmware. You can SSH into any of your UniFi devices, and run the ubnt-upgrade command with the proper file URL. This requires the device to be online and able to reach the internet.
ubnt-upgrade https://fw-download.ubnt.com/<insertfilepathhere>.bin
The best source to find the firmware URL is Ubiquiti’s community forums. Search for your device on this software releases page, and get the link to the firmware you want to install.
Another way to do this is by using the web interface. Under the devices tab, select your device, and click on the gear-shaped config icon. Paste the URL and hit the “custom upgrade” button. You don’t need the “ubnt-upgrade” command before the URL, that is only needed when you are using the command line.
Sources and Links
-Help article showing commands for retrieving log files.
-Ubiquiti’s SSH intro help article.
-Ubiquiti’s software releases page.
-Reddit thread with useful commands for the UDM and UDM-Pro.
Ssh Config Missing Page
I will continue to update this guide as I find more information about SSH access on the UDM and UDM-Pro. Until then, I have a lot of other posts where I talk about UniFi hardware and software:
Other Ubiquiti Guides and Reviews
Ssh Config Missing File
If you have more questions about Ubiquiti or anything in this post, leave a comment or contact me. I will do my best to point you in the right direction, or help in any way I can.