Category Archives: System Administration

Raspberry PI as a Router and WIFI Hotspot

Using a Raspberry PI as a Router and Wifi hotspot with a firewall for your internal LAN or household network is now possible. The Wifi hotspot can function as a hotspot for guests. This can be more secure then the cheap nasty routers supplied by your ISP with hard coded passwords.

Continue reading

Self-signed SSL Certificates

We can create self-signed SSL certificates when used in-house, when setting up Apache or a mailserver. We should always be using HTTPS and encrypted connections whenever we can. You know it makes sense. The majority of the time we can now use SSL certificates from Let’s Encrypt. They are free and once setup trouble free. Sometimes though we need a quick some self-signed SSL certificates while testing. This post takes you though how to create self-signed SSL certificates with OpenSSL. It also shows how to create one with multiple alternate names or SANs. Read the SSL documentation, its on the internet :).

Continue reading

Mail Server On Ubuntu 18.04 Part 4

Welcome to Mail Server on Ubuntu 18.04 Part 4. This is the fourth part of a series of blog posts. We will be adding some extra checking to postfix. This will allow you to effectively blacklist some domains and email addresses. We will also be adding checks for properly formatted domain names and checking the IP address against their DNS lookup.

Mail Server on Ubuntu 18.04 Part 1
Mail Server on Ubuntu 18.04 Part 2
Mail Server on Ubuntu 18.04 Part 3

Continue reading

Mail Server on Ubuntu 18.04 Part 3

Welcome to Mail Server on Ubuntu 18.04 Part 3. This is the third part of a series of blog posts. In this post we will be adding anti-virus and anti-spam along with some other tools to stop spam and viruses getting through to our mailserver.

Mail Server on Ubuntu 18.04 Part 1
Mail Server on Ubuntu 18.04 Part 2

  • Emails will be checked with anti-virus service ClamAV
  • Emails will be checked with anti-spam filters from Spamassassin
  • Grey listing of incoming mail servers with Postgrey

Continue reading

Mail Server on Ubuntu 18.04 Part 2

Welcome to Mail Server on Ubuntu 18.04 Part 2. This is the second part of a series of blog posts. The mailserver will use Postfix, Dovecot and Amavis. To see Mail Server on Ubuntu 18.04 Part1 follow the link.

In Mail Server on Ubuntu 18.04 Part 2 we will turn on the ability for any user to send and receive emails once they are known to the system via a MySQL database. This is called using virtual users. We will also turn on the ability to use encrypted connections with TLS.

Continue reading

Test Networking Lab Ubuntu On 18.04

Overview

I wanted to create a test networking lab Ubuntu on 18.04 to try out configurations without having to hack my real LAN about. I decided to use VirtualBox virtual machines as the software is freely available and works with Linux very nicely. For the network in the test networking lab Ubuntu on 18.04 we will need to separate from our own normal LAN. VirtualBox provides this in of the box. We simply set the network interfaces to use “Internal Network”. This way any gust VMs on the host within the internal network can only see each other.

Continue reading

Installing Munin on Ubuntu 16.04

Installing Munin on Ubuntu 16.04 is not the hard. Munin is a monitoring system that runs over the network for the local server and remote servers. It monitors all the basics out of the box. We can use it to monitor servers of all types to see what has happened and help find out why stuff broke or started to go slow.

Continue reading

Installing AWstats on Ubuntu 16.04 LTS

If you want to see loads of stats for your web site try Installing AWstats on Ubuntu 16.04 LTS. Number of visitor, Waht OS or Browser they used.

Install

Installing AWstats on Ubuntu 16.04 LTS and some additional packages necessary for the geo and net IP location stats.

sudo apt-get install awstats libgeo-ipfree-perl libnet-ip-perl

Continue reading

Mail Server on Ubuntu 16.04 Part 5

Welcome to Mail Server on Ubuntu 16.04 Part 5. This is the fifth part of a series of blog posts. We will be adding Roundcube, allowing your users to access their email over a secure HTTPS connection from any browser.

Mail Server on Ubuntu 16.04 Part 1
Mail Server on Ubuntu 16.04 Part 2
Mail Server on Ubuntu 16.04 Part 3
Mail Server on Ubuntu 16.04 Part 4

Continue reading

Mail Server on Ubuntu 16.04 Part 4

Welcome to Mail Server on Ubuntu 16.04 Part 4. This is the forth part of a series of blog posts. We will be adding some extra checking to postfix. This will allow you to effectively blacklist some domains and email addresses. We will also be adding checks for properly formatted domain names and checking the IP address against their DNS lookup.

Mail Server on Ubuntu 16.04 Part 1
Mail Server on Ubuntu 16.04 Part 2
Mail Server on Ubuntu 16.04 Part 3

Continue reading