Networking & Security
Configure IPs, ports, and firewall rules.
By Andy Wallace and 2 others3 authors9 articles
- Add extra IPv4 addresses to your VPSLearn how to add, remove, and persist additional IPv4 addresses on Linux and Windows VPS.
- Fix PuTTY “Connection timed out” when noVNC worksFind what stops SSH when the noVNC Console still shows your server, and connect again.
- Check which ports are open on your VPS firewallFind out why a port on your VPS doesn't answer and allow it in each firewall that filters it.
- Enable and troubleshoot port 25 on multiple VPS IPsLearn how to enable SMTP on all assigned IPs, fix routing and firewall issues, and bind your mail server correctly.
- Enable the firewall for your VPSBlock every port except the ones you use, without locking yourself out of SSH or Remote Desktop.
- Firewall rule orderRules are checked from the top and the first match decides. A ping example shows why order matters.
- Common firewall rules for a VPSReady-made rules for SSH, Remote Desktop, ping, websites and VPNs, with the order to create them in.
- SMTP port 25 unblock requirementsWho can ask for outgoing port 25 to be opened, and what to fill in on the request form.
- Changing a VPS primary IPA primary IP change is a manual request with a $10 fee, which can be waived only for an IP listed on AbuseIPDB or Spamhaus.