A quick reference for Ubuntu Server 26.04 LTS: updates, software, the ufw firewall, networking and what is new compared with earlier versions.
Our images use Ubuntu Server 26.04 LTS. Standard support for this version runs until April 2031. Log in as the ubuntu user and run administrator commands with sudo — for more detail, see How to connect to your server over SSH.
Updating
sudo apt update
sudo apt upgradesudo apt full-upgrade also installs updates that need packages to be removed or replaced. If a reboot is needed after an update, the file /var/run/reboot-required appears, and you will see “System restart required” when you log in. Before a major update, take a server snapshot.
Security updates are installed automatically every day: the image runs unattended-upgrades. To configure or turn it off, use sudo dpkg-reconfigure unattended-upgrades; the log is in /var/log/unattended-upgrades/.
Software
sudo apt install nginx | install |
sudo apt remove nginx | remove; purge removes the settings too |
apt search keyword, apt show nginx | find a package, view its description |
sudo apt autoremove | remove packages that are no longer needed |
Services and logs work as on any modern Linux: systemctl status nginx, journalctl -u nginx. Other common commands are in Basic Linux commands.
The ufw firewall
ufw is installed but switched off. Allow SSH first, then enable it — otherwise you will lose access:
sudo ufw allow OpenSSH
sudo ufw allow 80,443/tcp
sudo ufw enable
sudo ufw status verboseIf you do lose access, log in through the console in your control panel and run sudo ufw disable.
For how to open other ports, and what to do if a port doesn’t respond, see How to open a port on your server.
Networking
The address, gateway and DNS servers are set when the server is created; the file is /etc/netplan/50-cloud-init.yaml. To view them: ip -4 addr, ip route, resolvectl status. If you edit the network settings, apply them with sudo netplan try: if something goes wrong, the previous settings come back by themselves after two minutes.
What’s new in 26.04
- sudo and the core utilities have been rewritten in Rust. For everyday work nothing changes. If an old script doesn’t cope with something, the classic versions can be installed as packages:
sudo.wsandcoreutils-from-gnu. - SSH starts on the first connection (ssh.socket). If you change the port in the settings, run
sudo systemctl daemon-reloadandsudo systemctl restart ssh.socket, otherwise SSH keeps listening on the old port. - Time is synchronised by chrony: to check, run
chronyc tracking.
To see the system version, run cat /etc/os-release.
Didn’t find the answer? Ask our support team — we’ll help.