Guides tagged “firewall”
Step-by-step MdmHost guides about firewall, sorted A-Z.
76 guides · page 1 of 4
Advanced UFW rate limiting to prevent brute force attacks
Use ufw limit and custom before.rules entries to cap connection rates on SSH and mail ports, so password-guessing bots get blocked before they can try thousands of logins.
Advanced Windows Firewall: Blocking Specific Application Executables
Windows Firewall can filter by executable path, not only by port. This guide shows how to block a specific program inbound and outbound with PowerShell, and how to verify the rule.
Allow RDP port 3389 through your PC's firewall or antivirus
Your own computer's security software can block Remote Desktop to port 3389. Find the block, add a narrow exception for mstsc or TCP 3389, and keep protection switched on.
Allow, deny and temporarily ban IP addresses in CSF
Use CSF commands and the WHM interface to whitelist trusted IPs, permanently deny attackers, add temporary bans and ignore IPs in LFD, with the files behind each list.
Block an IP address or subnet with UFW
Block single IP addresses and whole CIDR ranges with ufw deny, place deny rules above your allow rules so they actually work, find attacking IPs in your logs and unblock them later.
Block thousands of IPs with firewalld ipsets
Create a hash:net ipset in firewalld, load a blocklist file into it, attach it to the drop zone and update entries later without rebuilding your whole firewall.
Blocked by Imunify360? How to check and unblock your IP
Why Imunify360 blocks IP addresses after failed logins or suspicious traffic, how to tell if you are blocked, how to pass the CAPTCHA and how to get an IP unblocked.
Change the Remote Desktop port safely
Open the new port in Windows Firewall first, change the RDP port in the registry, restart the service and connect on the new port.
Change the SSH port safely without locking yourself out
Move SSH to another port in the right order: firewall first, SELinux and Ubuntu socket activation handled, both ports tested, then port 22 closed.
Check the Windows Firewall rule for RDP port 3389
Find and verify the inbound TCP 3389 rule that lets Remote Desktop reach your server, recreate it if it was deleted and scope it without locking yourself out.
CIDR notation and subnets explained (/24, /32, /64)
Learn what CIDR suffixes like /24, /32 and /64 mean, how many addresses each covers, and how to use them safely in firewall allowlists and blocklists.
Combining Fail2ban with UFW and firewalld for Layered Defense
Fail2ban bans IPs with its own rules by default. Point its ban actions at UFW or firewalld so every ban lands in the firewall you already manage and audit.
Common server ports and what uses them
A practical list of the ports you meet on a VPS, from SSH and web to mail, databases and Remote Desktop, with the protocol and whether each should be public or private.
Configure firewall rules for a Virtualizor VPS
Protect your VPS with firewall rules: use Virtualizor's firewall where your provider enables it, or configure UFW or firewalld inside the VPS without locking yourself out.
Configure firewalld on AlmaLinux and Rocky Linux
Learn the firewalld basics on AlmaLinux and Rocky Linux: zones, opening services and ports, permanent versus runtime rules, and IP-restricted access.
Configure ModSecurity (Web Application Firewall) in Plesk
Enable ModSecurity in Plesk, choose a rule set, use detection-only mode, find blocked requests in logs, and switch off rules that cause false positives per server or domain.
Configure the Plesk Firewall extension: rules for web, mail and FTP
Install the Plesk Firewall extension, add rules for web, mail, FTP and custom ports, then apply them without locking yourself out of SSH.
Connect to RDP port 3389 from office, hotel or school Wi-Fi
Some office, hotel and campus networks block outbound Remote Desktop traffic on port 3389. Learn how to confirm the block and the safe ways to reach your server anyway.
DDoS protection basics for websites and servers
Understand what a DDoS attack is, the difference between network floods and application-layer attacks, and the practical steps that keep a hosted site or VPS online.
Delete, insert and reorder UFW rules safely
List UFW rules by number, delete them by number or by rule text, insert a rule at a set position and reset UFW without cutting off your own SSH session.
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