Server Administration

Ubuntu 20.x ~ DHCP Server Setup

Netplan.IO Interface Configuration network: ethernets: ens3: dhcp4: false dhcp-identifier: mac addresses: [ ] gateway4: nameservers: addresses: [, ] version: 2 Install isc-dhcp-server services apt -y install isc-dhcp-server Configure isc-dhcp-server /etc/default/isc-dhcp-server # Defaults for isc-dhcp-server (sourced by /etc/init.d/isc-dhcp-server) # Path to dhcpd’s config file (default: /etc/dhcp/dhcpd.conf). DHCPDv4_CONF=/etc/dhcp/dhcpd.conf DHCPDv6_CONF=/etc/dhcp/dhcpd6.conf # Path to dhcpd’s […]

TACACS+ ~ Linux TACACS+ Authentication using Active Directory

This guide will walk you through the setup of a Linux based TACACS+ Authentication Server, using Ubuntu 18.04 (tested on Ubuntu 16.04 as well) that authenticates against a Windows Active Directory LDAP(S). This guide assumes that you are familiar with installing and configuring a Ubuntu Server and can deploy or have already deployed a Windows […]

Setting up an SSH Key

We will always recommend using an SSH Key for password-less access to remote servers, especially when authenticating to the server via the root account. All of our servers have root password access disable by default, so using an SSH key is the only option.  To help those that do not already have one setup, here […]

EVE-NG ~ How to Expand the LVM Disk

The community edition of EVE-NG pre-built OVA comes with a 40G disk. There are instructions on how to extend this by adding additional disks, however, I wanted to maintain a single disk and expand it to a larger size. Below are the instructions on how to safely accomplish this without loosing data. 1 — Expand […]

CentOS 6 ~ Percona MySQL XtraDB Multi-Master Clustering

Introduction In this how-to article, we will walk you through the procedures for installing and maintaining a Single-Site Multi-Master MySQL Cluster solution with Load-Balancing services. We will be using Percona XtraDB Cluster Server as our base MySQL database platform, as it has all the necessary components and has built in support for an active/active high availability and […]

Windows Server 2016 ~ How to disable IPv6 Temporary Addressing

One of the added security features with IPv6 addressing is “Temporary address interface identifiers”. What this means from an administration perspective is that after every reboot, the IPv6 address that is presented to the network changes ….. which makes things like DNS / FW rules etc a nightmare to manage in a corporate / enterprise scenario […]

Ubuntu 14.04 ~ Setting up a Complete Mail Server

Introduction In this how-to article, we will walk you through building a complete mail server on Ubuntu 14.04.  Building a Linux mail server from ground up can be a painful process unless you do it day in and day out, but we are going to show you have to do it as least painful as […]

CentOS ~ Secure BIND9 DNS Server

Introduction In this how-to article, we will walk you through the installation of a secure BIND9 authoritative DNS server on CentOS 6.x BIND is open source software that implements the Domain Name System (DNS) protocols for the Internet. It is a reference implementation of those protocols, but it is also production-grade software, suitable for use in […]

Windows Server 2016 ~ Configure NTP Time Source

On Windows Server, you can manually configure the NTP time sync service to use outside servers. To do this, execute the following command: w32tm /config “/” /update w32tm /resync To confirm the peer list, execute w32tm /query /peers Within a few seconds, your server time will now be in sync with the public […]

Ubuntu ~ GRE Tunnel to Cisco Router

Ubuntu Server Tunnel auto tun1 iface tun1 inet static address {{local-private-ip4-address}} netmask pre-up iptunnel add tun1 mode gre local {{local-public-ip4-address}} remote {{remote-public-ip4-address}} ttl 255 up ifconfig tun1 multicast pointopoint {{remote-private-ip4-address}} post-down iptunnel del tun1 If you are running a firewall on your Ubuntu server, you will need to make sure to allow GRE tunnelling […]