My Linux

I had originally written this tutorial for xmodulo.com This tutorial will discuss how to set up a working mail server in Ubuntu or Debian. As we know, the two major protocols used in a mail server are SMTP and POP/IMAP. In this tutorial,  postfix  will be used for SMTP, while dovecot  will be used for POP/IMAP. Both are open source, stable and highly customizable. Please note that securing a mail server is beyond the scope of this tutorial, and will be covered in future tutorials. Prerequisites Each domain should have a DNS server. It is recommended NOT to use a live domain for testing purposes. In this tutorial, a test domain  example.tst  will be used in a lab environment. A DNS server for this hypothetical domain should have the following records at the least. Forward zone for example.tst: IN MX 10 mail.example.tst. mail.example.tst. IN A 192.168.10.1 Reverse zone for example.tst: 192.168.10.1 IN PTR mail.example.tst. While configuring a li...

I had originally written this tutorial for xmodulo.com SNMP (or Simple Network Management Protocol) is used to gather data on what is going on within a device, such as load, hard disk states, bandwidth. These data are used by network monitoring tools such as Cacti to generate graphs for monitoring purposes. In a typical deployment of Cacti and SNMP, there will be one or more SNMP-enabled devices, and a separate monitoring server where Cacti collects SNMP feeds from those devices. Please keep in mind that all the devices that need to be monitored must be SNMP enabled. In this tutorial, we will be configuring Cacti and SNMP on the same Linux server for demonstration purpose. Configure SNMP on Debian or Ubuntu To install SNMP agent ( snmpd ) on a Debian-based system, run the following command. root@server:~# apt-get install snmpd Then edit its configuration like the following. root@server:~# vim /etc/snmp/snmpd.conf # this will make snmpd listen on all interfaces agentAd...

I had originally written this tutorial for xmodulo.com . Any system admin working in a service provider network would certainly agree that  Cacti  is one of the most widely used tools in network management solutions. It is open source, has built in user authentications and user permission features, shipped with frequently used graph templates like bandwidth, 95th percentile, hard disk usage, CPU usage, load average, RAM statistics and many more. Cacti also supports 3rd party templates and plugins. If those are not enough, one can write and use one’s own templates, and that is the beauty of open source software. Without further ado, let us jump in on how to deploy a Cacti server on Linux. Install and Configure Cacti on Debian or  Ubuntu Before starting, we make sure that our server is in sync with the software repository. root@server:~# apt-get update Now we start installing Cacti. root@server:~# apt-get install cacti This step will install a lot of ad...