CentOS / RHEL 7 / Debian – Disable IPv6

If network troubleshooting leads you to believe there’s an issue with IPv6, you may need to shut down that protocol on your Linux machines. Since some hardware doesn’t take advantage of IPv6 (and most admins are still working with IPv4), a temporary and easy solution is to disable IPv6. Read More …

CentOS / RHEL 7 – Regenerate UUID for Network Cards (Physical and Virtualized Environments)

Usually, when cloning VMs on virtualized systems (Hyper-V or VMware, for example) an issue could occur related to vNICs: a vNIC could be renamed and so no more the same of the old VMs (obviously). Read More …

CentOS / RHEL – Managing Networking Service

One of the most common activities on a Linux system is, usually, modify some networking parameters to adapt the system to the actual network; so how can we restart networking service using command line options without restarting the whole system? How can I start / stop and restart networking service on a CentOS/RHEL 7 based system? Read More …

Linux – Removing Apache HTTP Server

Removing Apache HTTP Server ensures that, it’s existing files or services will not create conflict when we install Apache HTTP Server from the source code. Read More …

Enable EPEL Repository (RHEL/CentOS 7.x/6.x/5.x)

EPEL (Extra Packages for Enterprise Linux) is open source and free community based repository project from Fedora team which provides 100% high quality add-on software packages for Linux distribution including RHEL (Red Hat Enterprise Linux), CentOS, and Scientific Linux. Read More …

Postfix – SMTP E-Mail Relay for Office 365

Postfix is a flexible mail server that is available on most Linux distribution. Though a full featured mail server, Postfix can also be used as a simple relay host to another mail server, or smart host. This tutorial will describe how to configure Postfix as a relay through Office 365 service, so using Exchange Online. Read More …

Test Bind DNS Zone File Replication to Slave Servers (CentOS)

The Scenario You are on-boarding/bringing up a new Bind DNS server (say NSHost3 – 198.164.12.103) to replace/upgrade your existing Bind Read More …