DNS

In some situations could be needed to know exactly which DNS server is being used by an Ubuntu host. There are several ways to get this info, however the best option I have found is to use the resolvectl service. This service is in charge of the name resolution of the local applications. You can use it executing resolvectl status or just resolvectl. The command will return the DNS servers configured in each network interface, and which one is currently being used. ...

Introduction Nowadays, the knowledge to install a mail server is an important task for any System Administrator. In our case, we are going to see how to deploy a mail server with Postfix on Ubuntu. About Postfix Postfix is a free and open-source MTA (Mail Transfer Agent) which routes and delivers electronic mail (e-mails). As an SMTP server, Postfix implements a first layer of defense against spambots and malware. Can be used to send and receive e-mail. This is the default MTA software on all Linux distributions. ...