The migration arises from the need for php 7 support. I must admit I’ve been successfully fooled by the versioning of php and CentOS. My old system is CentOS6 where only php5 is supported. I mean you cannot use “yum…

Although the command to create a symbolic link in Linux is very simple, I never remember it. Every time I need to create a soft(symbolic) link in CentOS, I have to search google for the answer. In fact, the linux…

I want to share some pdf files on a free website. I do not want to buy a domain name. I do not want to buy a hosting space. I want to use a free space. I do not want…

When setting up a new site in WinSCP, you have the option to save your password so you won’t be prompted to input  a password to login the site. This is convenient in most cases except you want to retrieve…

As an outlook user, you have a outlook mailbox. When you configure your email client such as outlook, outlook express,etc., you will be asked to input a SMTP server. You should input smtp.live.com, port 587 here. This is the smtp…

If you’ve read my article on how to use openssl to send emails, you may encounter some problem when applying that method to certain kind of SMTP servers such as outlook SMTP server. openssl s_client  -connect smtp.live.com:587 WARNING: can’t open…

If you ask me what part of wireshark is the most difficult to learn, I would say it is the filter. Do you know how to filter packets belong to specific ip address? ip=xx.xx.xx.xx ipaddr=xx.xx.xx.xx ipaddress=xx.xx.xx.xx ip:xx.xx.xx.xx ipaddr:xx.xx.xx.xx ipaddress:xx.xx.xx.xx ip==xx.xx.xx.xx…

There are tons of documents on SPF and DKIM but I find none explains them clearly. All the articles say they are used to prevent email spoofing but none tells you how they can fight against email spoofing or forging…

I’ve composed several articles talking about installing proftpd on CentOS. By reading my posts, you should know how to install proftpd with or without Sentora. You should be able to config proftpd to use ssl for secure file transfer. Thing…

When you browse a website, you may notice a little icon on top of the web page(on the tab header of the browser, right in front of the site title). This is called favicon meaning “Favorites Icon”.  As a webmaster,…