Sendinblue SMTP relay host

Configure Postfix to send e-mail using Sendinblue as SMTP server

Introduction Some time ago I tried to configure a SMTP server in a host in the cloud, but because of some restrictions, the emails from that server were bounced. The problem was that the hosting provider didn’t configure the PTR DNS entries (more about DNS PTR entries) for some kind of hostings. When this happens the best solution is to use a SMTP relay server, by this way that server is in charge of the final delivery of the emails. There are some services such us Sendinblue which offers 300 mails per day in the free plan. I believe it’s enough for a normal use of a mail server. ...

November 11, 2022 · 3 min · Yvoictra
Mail Server

How to Install a Mail Server in Ubuntu with Postfix

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. ...

July 27, 2022 · 15 min · Yvoictra
Test bandwidth with iPerf

How to test bandwidth with iPerf

iPerf is a tool designed to test the bandwidth between two hosts using the network. It is a really simple, powerful CLI which allows generating traffic / load TCP or UDP between 2 hosts. You could use to measure the maximum bandwidth of the network between a client and a server. It can be used to do stress tests of the Ethernet, Wi-Fi or of your ISP. iPerf2 vs iPerf3, what is the difference? There has been different versions of this tool in the last years. It started ttcp from the National Laboratory for Applied Network Research (NLANR), and then it was developed iPerf (iPerf 2). iPerf3 is a new implementation from scratch, with the goal of a smaller, simpler code base, and a library version of the functionality that can be used in other programs. The functionality between iPerf2 and iPerf3 are mostly compatible, however you should know they use different ports by default. In iPerf2, the default port is 5001, and in iPerf3, 5201. ...

July 18, 2022 · 7 min · Yvoictra
CSGO Ubuntu Ubuntu

How to install a CS GO (Counter-Strike: Global Offensive) server in Ubuntu 20.10

Some people are interested in have a private server in order to play CS GO (Counter-Strike: Global Offensive) with their friends. The process is easy to follow. What is needed? A server Memory: At least 2GB RAM (I recommend 4GB) Disk: At least 15 GB os disk space CPU architecture: x86 (ARM not supported) A Valve account Create a new user First of all, it is important to create a new user in Linux in order to prevent CS GO server possible hacking to affect your Linux node. ...

December 8, 2020 · 7 min · Yvoictra

How to add aliases to your Linux

Using a Linux Operating System, there is a high level of customization, depending on your preferences or needs. One important thing is to create aliases to the most common commands in order to optimize the time you use. In mi case, I love to use .. instead of cd .. or update to update all my Linux software pending updates. Here I put my list of aliases for Ubuntu (based on Debian) or CentOS (based on RHEL) distribution. It is not big but it is what I mostly use in the servers I have with Linux. ...

October 24, 2020 · 2 min · Yvoictra

How to resolve LAN hostnames with Ubuntu

By default, Ubuntu desktop installation will provide DNS resolving configured, however in Ubuntu server installation avahi-daemon (or mdnsresponder) is needed to be installed to provide local LAN DNS resolution. In my case, i found the error “Temporary failure in name resolution” when I tried to resolve a machine of my LAN from Ubuntu. yvoictra@zoar:~$ ping erie.local ping: erie.local: Temporary failure in name resolution To solve this issue, there is no need to install a DNS server in the LAN. We can use the mDNS (Multicast Domain Name System) protocol. This protocol is used to resolve host names in a small network (LAN). The mDNS service can be contacted using UDP queries over port 5353. The mDNS protocol is published as RFC6762 and implemented by the Apple Bonjour and avahi-daemon services. ...

April 19, 2020 · 2 min · Yvoictra
Sudo Ubuntu

How to activate SUDO in Ubuntu for a user

The sudo command allows users to run programs with the security privileges of another user, by default, the root user. First if all, the user should be created in the system if it doesn’t exists yet. On Ubuntu systems, by default members of the group sudo are granted to sudo command access. Once the user is created, from root user, or a user with sudo access, you have to execute this command to add the user to sudo group. ...

April 18, 2020 · 1 min · Yvoictra
vnStat

How to monitor network traffic on Ubuntu using vnStat

Monitoring network traffic or bandwitdh usage is a must in a SysAdmin tasks. There are many differents tools to manage this monitoring, but one of my favorites is vnStat. The main advantage of this tool is the simplicity of its usage. Installation With Ubuntu, the way to install this tool is with apt. sudo apt install vnstat First steps Once installed, it is important to know which interfaces are going to be monitoried. For this, you can use next command ...

April 3, 2020 · 2 min · Yvoictra