Web development

Items filtered by date: October 2021

So here is the explanation of what these three elements are, and how we should configure them to appear, even at a technical level, as "handsome as possible" in the face of anti-spam filters.



Sender Policy Framework (SPF) is an email validation system designed to prevent spam by detecting techniques commonly used by cybercriminals such as spoofing, a common vulnerability, by verifying the sender's IP address.

Published in System Administration
Sunday, 31 October 2021 09:19

How to install SSH server in Ubuntu

The procedure to install a ssh server in Ubuntu Linux is as follows:

  1. Open the terminal application for Ubuntu desktop.

  2. For remote Ubuntu server you must use BMC or KVM or IPMI tool to get console access

  3. Type sudo apt-get install openssh-server

  4. Enable the ssh service by typing sudo systemctl enable ssh

  5. Start the ssh service by typing sudo systemctl start ssh

  6. Test it by login into the system using ssh user@server-name

Published in Ubuntu
Sunday, 31 October 2021 09:17

Enable root login over SSH

Enable root login over SSH:

 As root, edit the sshd_config file in /etc/ssh/sshd_config:

Published in System Administration

Problem: Using Putty SSH to log in some hosts, I got “Couldn’t agree a key exchange algorithm (available: This email address is being protected from spambots. You need JavaScript enabled to view it., ECDH-sha2-nistp521, ECDH-sha2-nistp384, ECDH-sha2-nistp256)”.

Published in System Administration

If your IP or mailserver is blacklisted on UCEPROTECT, you don't have to worry about appearing on this

This blacklist is a scam, since they have blocked millions of legitimate IPs and request a financial amount in exchange for removing the IPs from their list.

We must be wary of blacklists where the payment of money is required for the elimination of your IP.

Published in Dedicated Servers

If you keep coming across the prompt “ DMARC policy not enabled” for your domain, that means that your domain is not protected against spoofing and impersonation with DMARC email authentication. You may often encounter this prompt while conducting reverse DNS lookups for your domain. However, it often has an easy fix to it. Through this article, we are going to take you through the various steps you need to implement to configure DMARC and set up the right policy for your domain so that you never have to come across the “DMARC policy is not enabled” prompt again!

Published in Dedicated Servers

How do I install PHP extension called phpredis (php-redis) for interfacing with Redis cluster on CentOS 8 or RHEL 8?

The phpredis extension provides an API for communicating with the Redis key-value store. This Redis client implements most of the latest Redis API. One can use php-redis to talk with Redis server or cluster. This page provides instructions on how to install and configure the phpredis on CentOS 8 or RHEL 8 for PHP version 7.4.


Published in Centos