Guides tagged “firewall”
Step-by-step MdmHost guides about firewall, sorted A-Z.
91 guides · page 3 of 5
Imunify360 firewall settings: ports, country blocking and DoS protection (root guide)
Configure the Imunify360 firewall as root: open and close TCP/UDP ports, block countries, enable DoS protection, and avoid locking out cPanel, mail or SSH.
Imunify360 firewall: blacklist IPs, block countries and manage ports
Use the Imunify360 firewall in WHM to blacklist IPs and subnets, block whole countries, understand the graylist, and open or close ports from the UI or CLI.
Imunify360 firewall: whitelist, blacklist and grey list explained
How the Imunify360 firewall lists work (white, black and grey), when an IP should be whitelisted, how to request it on MdmHost and the risks of whitelisting.
Imunify360 on cPanel hosting: what it protects and how to use it
An overview of Imunify360 on MdmHost: malware scanning, Proactive Defense, the firewall, WAF and WebShield, what you see in cPanel and what MdmHost manages for you.
Imunify360 WebShield and CAPTCHA pages explained
Why visitors sometimes see an Imunify360 CAPTCHA or challenge page, how WebShield and the grey list work, and what to do if real visitors or bots you need are challenged.
Install and configure CSF and LFD firewall on a cPanel/WHM server
Install ConfigServer Security & Firewall (CSF) with LFD on a WHM server, set the essential csf.conf options, take it out of testing mode and manage it from WHM.
Install SQL Server Express on a Windows VPS
Install SQL Server Express and SSMS, create a database and app login, and allow remote connections only from your own IP address.
iptables basics: list, allow, drop and save rules
Learn how iptables chains and rule order work, then build a small ruleset that allows SSH and web traffic, drops everything else and can be edited by line number.
Linux firewall basics with nftables and iptables
Understand how the Linux kernel firewall works, write a minimal stateful nftables ruleset for a web server, translate iptables rules and make rules persistent.
Linux Firewall: Using iptables to Implement Connection Tracking Limits
Cap new and simultaneous connections on a Linux VPS with iptables conntrack, limit, connlimit and hashlimit rules, and size the conntrack table so it does not fill up.
Linux Firewall: Using nftables to Drop Malformed Packets and Attack Vectors
Build nftables chains that drop malformed packets, invalid conntrack states and common scan patterns before they reach your services, then verify the counters.
Linux Firewall: Using UFW to Block Specific Source IP Ranges Automatically
Block a source IP range in UFW with one command, then keep a blocklist file and a cron job that re-applies it so new ranges are dropped without manual work.
Linux server hardening checklist for a new VPS or dedicated server
A practical Linux server hardening checklist: updates, users and sudo, SSH keys, firewall, Fail2Ban, closing unused services, automatic security patches, logging and backups.
Lock down SSH on a Linux VPS: a complete checklist
A step-by-step SSH hardening checklist for Linux VPS and WHM servers: keys only, no root password login, firewall limits by IP, brute-force bans and safe testing.
Locked out by your firewall? How to get back into your VPS
If a firewall rule blocked SSH, you can still reach your server through the browser console in your VPS provider's control panel. Disable the firewall, fix the rule and turn it back on safely.
Make iptables rules survive a reboot
iptables rules live in memory and disappear on reboot. Save them with netfilter-persistent on Debian and Ubuntu or iptables-services on AlmaLinux and Rocky Linux.
Manage Windows Defender Firewall on Windows Server with PowerShell
Create, list, restrict and remove Windows Defender Firewall rules on a Windows VPS using the GUI and PowerShell, including limiting RDP to your IP and logging drops.
Migrate iptables rules to nftables
Move an existing iptables firewall to native nftables. Check whether you run iptables-nft or legacy, export with iptables-save, translate the rules, test them and switch the boot service.
Open and close ports in CSF (TCP_IN, TCP_OUT, UDP_IN, UDP_OUT)
Edit the CSF port lists to open a port for a new service, close ports you do not use, and restrict a port such as SSH to trusted IPs on a cPanel/WHM server.
Open ports with UFW: single ports, ranges and trusted IPs
Open TCP and UDP ports in UFW, allow port ranges, limit access to one IP or subnet, label rules with comments and confirm everything with ufw status numbered.
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