About your GitHub Enterprise Server instance's firewall
GitHub Enterprise Server uses Ubuntu's Uncomplicated Firewall (UFW) on the virtual appliance. For more information see "UFW" in the Ubuntu documentation. GitHub Enterprise Server automatically updates the firewall allowlist of allowed services with each release.
After you install GitHub Enterprise Server, all required network ports are automatically opened to accept connections. Every non-required port is automatically configured as deny, and the default outgoing policy is configured as allow. Stateful tracking is enabled for any new connections; these are typically network packets with the SYN bit set. For more information, see "Network ports."
The UFW firewall also opens several other ports that are required for GitHub Enterprise Server to operate properly. For more information on the UFW ruleset, see the UFW README.
Viewing the default firewall rules
- SSH into your GitHub Enterprise Server instance.
$ ssh -p 122 admin@HOSTNAME - To view the default firewall rules, use the
sudo ufw statuscommand. You should see output similar to this:$ sudo ufw status > Status: active > To Action From > -- ------ ---- > ghe-1194 ALLOW Anywhere > ghe-122 ALLOW Anywhere > ghe-161 ALLOW Anywhere > ghe-22 ALLOW Anywhere > ghe-25 ALLOW Anywhere > ghe-443 ALLOW Anywhere > ghe-80 ALLOW Anywhere > ghe-8080 ALLOW Anywhere > ghe-8443 ALLOW Anywhere > ghe-9418 ALLOW Anywhere > ghe-1194 (v6) ALLOW Anywhere (v6) > ghe-122 (v6) ALLOW Anywhere (v6) > ghe-161 (v6) ALLOW Anywhere (v6) > ghe-22 (v6) ALLOW Anywhere (v6) > ghe-25 (v6) ALLOW Anywhere (v6) > ghe-443 (v6) ALLOW Anywhere (v6) > ghe-80 (v6) ALLOW Anywhere (v6) > ghe-8080 (v6) ALLOW Anywhere (v6) > ghe-8443 (v6) ALLOW Anywhere (v6) > ghe-9418 (v6) ALLOW Anywhere (v6)
Adding custom firewall rules
Warning: Before you add custom firewall rules, back up your current rules in case you need to reset to a known working state. If you're locked out of your server, contact GitHub Enterprise Support or GitHub Premium Support to reconfigure the original firewall rules. Restoring the original firewall rules involves downtime for your server.
- Configure a custom firewall rule.
- Check the status of each new rule with the
status numberedcommand.$ sudo ufw status numbered - To back up your custom firewall rules, use the
cpcommand to move the rules to a new file.$ sudo cp -r /lib/ufw ~/ufw.backup
After you upgrade your GitHub Enterprise Server instance, you must reapply your custom firewall rules. We recommend that you create a script to reapply your firewall custom rules.
Restoring the default firewall rules
If something goes wrong after you change the firewall rules, you can reset the rules from your original backup.
Warning: If you didn't back up the original rules before making changes to the firewall, contact GitHub Enterprise Support or GitHub Premium Support for further assistance.
- SSH into your GitHub Enterprise Server instance.
$ ssh -p 122 admin@HOSTNAME - To restore the previous backup rules, copy them back to the firewall with the
cpcommand.$ sudo cp -f ~/ufw.backup/*rules /lib/ufw - Restart the firewall with the
systemctlcommand.$ sudo systemctl restart ufw - Confirm that the rules are back to their defaults with the
ufw statuscommand.$ sudo ufw status > Status: active > To Action From > -- ------ ---- > ghe-1194 ALLOW Anywhere > ghe-122 ALLOW Anywhere > ghe-161 ALLOW Anywhere > ghe-22 ALLOW Anywhere > ghe-25 ALLOW Anywhere > ghe-443 ALLOW Anywhere > ghe-80 ALLOW Anywhere > ghe-8080 ALLOW Anywhere > ghe-8443 ALLOW Anywhere > ghe-9418 ALLOW Anywhere > ghe-1194 (v6) ALLOW Anywhere (v6) > ghe-122 (v6) ALLOW Anywhere (v6) > ghe-161 (v6) ALLOW Anywhere (v6) > ghe-22 (v6) ALLOW Anywhere (v6) > ghe-25 (v6) ALLOW Anywhere (v6) > ghe-443 (v6) ALLOW Anywhere (v6) > ghe-80 (v6) ALLOW Anywhere (v6) > ghe-8080 (v6) ALLOW Anywhere (v6) > ghe-8443 (v6) ALLOW Anywhere (v6) > ghe-9418 (v6) ALLOW Anywhere (v6)