Articles That Might Interest:

SASE & SD-WAN Networks

How To Secure Your SD-WAN. Comparing DIY, Managed…

With so much enterprise network traffic now destined for the cloud, backhauling traffic across an expensive MPLS connection to a data center to apply security policy no longer makes sense. Software-d…

Routing

The IP Routing Process - Step-by-Step Analysis

We are going to analyse what happens when routing occurs on a network (IP routing process). When I was new to the networking area, I thought that all you needed was the IP Address of the machine you…

Cisco Firewalls

Cisco ASA5500 (5505, 5510, 5520, etc) Series Fire…

The Cisco ASA 5500 series security appliances have been around for quite some time and are amongst the most popular hardware firewalls available in the market. Today Firewall.cx takes a look at how t…

VLAN Networks

VLANs - Access & Trunk Links

If you've read our previous article The VLAN Concept - Introduction to VLANs then you should feel comfortable with terms such as 'VLAN', 'Static & Dynamic VLANs', however this is just…

Cisco Services & Technologies

How to Fix Cisco VPN Client Error 51 – Unable to…

Apple Mac OS X users are frequently faced with the Cisco VPN Client Error 51 - Unable to Communicate with the VPN Subsystem as shown in the screenshot below: When this error is produced, users wil…

Ethernet Protocol, CSMA/CD, Collisions

Early Ethernet Collisions

In this example, we will refer to an imaginary Ethernet network consisting of Stations A and B and any number of other stations. The status of the network is such that the wire is idle (nobody is tal…

Cisco Services & Technologies

Troubleshooting Cisco VPN Client Windows 7 - How…

This article shows how to fix the Cisco VPN Reason 442: Failed to enable Virtual Adapter error on the Windows 7 (32bit or 64bit) operating system. If you are a Windows 7 user, it's most likely you've…

ManageEngine Firewall Analyzer

7 Essential Firewall Management Strategies for Ma…

A firewall appliance is a fundamental pillar of network security, acting as the first line of defense against cyber threats. However, its strength is only as good as its configuration, monitoring…

Network Fundamentals

Hubs & Repeaters

Network hubs were once the primary method of interconnecting network devices to create a local area network (LAN). Hubs were inexpensive, easy to install, and provided a simple means of connecting mu…

Cisco Data Center (Nexus/UCS)

NEXUS NX-OS: Useful Commands, CLI Scripting, Hint…

Whether you’re new to Cisco Nexus switches or have been working with them for years this article will show how to get around the Nexus NX-OS using smart CLI commands and parameters, create your…

Windows Servers

Configuring Windows Server Roaming Profiles

Windows roaming profiles allow the mobile users of a company to always work with their personal settings from any network computer in a domain. Roaming profiles are a collection of personal user sett…

TCP - UDP Protocol Analysis

Transmission Control Protocol - Part 3: The TCP H…

This article shows the TCP Header and Segment. We explain where the TCP Header and Segment are located in an Ethernet frame and also briefly view the available options in the TCP Header. Our easy-to-…