linux_wiki:network_services_overview_smtp

Network Services Overview SMTP

General Information

This page covers the Network Services objectives, specifically for SMTP.

Network Services Objectives

  • Install the packages needed to provide the service
  • Configure SELinux to support the service
  • Use SELinux port labeling to allow services to use non-standard ports
  • Configure the service to start when the system is booted
  • Configure the service for basic operation
  • Configure host-based and user-based security for the service

Lab Setup

The following virtual machines will be used:

  • server1.example.com (192.168.1.150) → Configure SMTP null client (on the exam)
  • server2.example.com (192.168.1.151) → Configure central mail server for client testing (NOT on the exam)

Install the packages needed to provide the service

Install the service

yum install postfix

Configure SELinux to support the service

Use SELinux port labeling to allow services to use non-standard ports

Configuring the <service-name> with a non standard port and allowing port access with selinux.

NOTE: “man semanage-port” has examples for allowing non-standard ports!


Configure the service to start when the system is booted

Check Current Service Status

systemctl status postfix
  • Also displays if the service is enabled or disabled


Enabling a service to start on boot

systemctl enable postfix

Configure the service for basic operation

Enable and Start the service

systemctl enable postfix
systemctl start postfix

Configure host-based and user-based security for the service

Allow access through the firewall

firewall-cmd --permanent --add-service=smtp
firewall-cmd --reload

  • linux_wiki/network_services_overview_smtp.txt
  • Last modified: 2019/05/25 23:50
  • (external edit)