Firewall & Security Hardening

20 articles

Articles

Set the Firewall for Your VPS

Your VPS has a firewall on the host, outside the server. It decides which incoming traffic reaches your VPS. [[tldr]] On the Firewall tab, click Add rule, choos...

18Updated 2 days ago

Read article

Why Outgoing Mail Ports 25 and 465 Are Blocked on Your VPS

To keep our IP addresses off spam blocklists, every new VPS has outbound ports 25 and 465 blocked. Port 587 works. [[tldr]] Send through a mail service with a l...

Intermediate2 min19Updated 2 days ago

VPS Security Hardening Checklist

A new VPS can be reached from the whole internet the moment it goes live, and automated bots start trying its SSH port within minutes. This checklist is the sho...

Advanced7 min631Updated 2 days ago

Setting Up a Firewall on Your VPS (UFW/iptables)

A firewall on your VPS blocks every inbound connection except the ports your services use. On a Domain India VPS you manage it yourself: use UFW on Ubuntu or De...

Advanced6 min913Updated 2 days ago

The Production-Ready VPS Playbook: OS Hardening, Gateways, TLS, Observability & Ops

Getting an app to run on a fresh VPS takes an afternoon. Keeping it safe, observable and recoverable takes a checklist. This playbook is that checklist for your...

Advanced10 min1,318Updated 24 Sept 2026

Modern Firewall Management with nftables on RHEL-Based Systems (AlmaLinux, CentOS, Rocky Linux)

nftables is the packet-filtering framework in the Linux kernel that replaced iptables. On AlmaLinux, Rocky Linux and other RHEL-based systems it sits underneath...

Advanced8 min5,454Updated 1 weeks ago

Managing CSF Firewall Rules on CentOS 8 with nftables

ConfigServer Security & Firewall (CSF) was written for iptables, but on CentOS 8 and its successors, AlmaLinux and Rocky Linux 8 and 9, the kernel firewall is n...

Advanced8 min2,807Updated 23 Sept 2026

How to Diagnose and Resolve CSF IP Blocks: A Step-by-Step Guide

CSF (ConfigServer Security & Firewall) and its login-failure daemon, LFD, block an IP address that fails to log in too often. When that happens to you, the serv...

Advanced6 min5,352Updated 1 Oct 2026

DDoS Attacks: Types and How to Protect Your Website

A distributed denial-of-service (DDoS) attack floods a website or server with traffic from many machines at once, usually hijacked devices in a botnet, until re...

Advanced9 min2,748Updated 3 Oct 2026

Installing and Optimizing CSF: A Comprehensive Guide

ConfigServer Security & Firewall (CSF) is a firewall manager and login-failure daemon for Linux servers, long popular on servers running cPanel or DirectAdmin. ...

Advanced10 min2,373Updated 24 Sept 2026

Resolving Temporary IP Blocks Due to Failed Login Attempts

If your website, webmail, FTP or control panel suddenly times out on your office or home connection but works on mobile data, the server's firewall has most lik...

Advanced7 min3,405Updated 1 Oct 2026

Understanding DDoS Mitigation Services: Safeguarding Your Online Assets

A DDoS mitigation service filters attack traffic away from your website or server so real visitors can still get through. Large floods can only be stopped befor...

Advanced7 min1,757Updated 24 Sept 2026

Mitigating DDoS Attacks Using CSF: A Comprehensive Guide

ConfigServer Security & Firewall (CSF) is a firewall and login-failure daemon widely used on Linux servers with cPanel or DirectAdmin. It can soften small flood...

Advanced9 min3,880Updated 1 weeks ago

How to Check for DDoS Attacks or Excessive Traffic from Specific IPs and Take Appropriate Actions

A sudden slowdown, a flood of 508 or 503 errors, or a bandwidth graph that jumps overnight can mean an attack, an aggressive bot, or simply a popular day. This ...

Advanced10 min3,672Updated 26 Sept 2026

Essential Security and Optimization Tips for Your VPS

A VPS gives you a whole Linux server with root access, and with it the job of keeping that server secure and fast. This guide is a practical checklist for your ...

Advanced9 min3,422Updated 3 Oct 2026

Networking and IP Management

Networking on your own server comes down to three jobs: giving the server the right IP addresses, pointing your domain names at them, and checking that traffic ...

Advanced10 min2,992Updated 2 days ago

CSF Blocklist and Multiple Login Failures: How Clients Can Protect Themselves

Our cPanel and DirectAdmin shared hosting servers run a firewall called CSF (ConfigServer Security & Firewall). Together with its login monitor, it blocks any I...

Advanced7 min4,524Updated 1 Oct 2026

As a cPanel end user, how you can identify if CSF has blacklisted your IP and how to fix it

If your website, cPanel, webmail or email app suddenly times out on your office or home connection but works on mobile data, the server's firewall has most like...

Advanced6 min2,624Updated 23 Sept 2026

how you can identify if CSF has blacklisted your IP and how to fix it - VPS

ConfigServer Security & Firewall (CSF) is a firewall for Linux servers, and its companion daemon, LFD, watches the logs and blocks IP addresses that fail to log...

Advanced7 min6,618Updated 26 Sept 2026

I can't reach my server: have I been blocked?

Your website, cPanel, webmail, FTP or email stops working for you, but a colleague or customer says it opens fine for them. In most cases the server itself is r...

Advanced11 min90,750Updated 30 Sept 2026