Articles That Might Interest:

Cisco Services & Technologies

Comparing Cisco VPN Technologies – Policy Based v…

Virtual Private Networks constitute a hot topic in networking because they provide low cost and secure communications between sites (site-to-site VPNs) while improving productivity by extending corpo…

Palo Alto Networks

Complete Guide: Configuring IPSec VPN between Pal…

This article will show you how to configure an IPSec VPN tunnel between a Palo Alto firewall (all PANOS versions) and Meraki MX security appliance. Our comprehensive guide includes IPSec VPN setup fo…

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…

Network Protocols

Trivial File Transport Protocol - TFTP

TFTP is a file transport protocol and its name suggests it's something close to the FTP protocol (File Transfer Protocol), which is true .. to a degree. TFTP isn't very popular because it's not reall…

Ethernet Protocol, CSMA/CD, Collisions

What is CSMA/CD ?

CSMA/CD stands for Carrier Sense Multiple Access with Collision Detection. It refers to the means of media access, or deciding "who gets to talk" in an Ethernet network. A more elegant term for "who…

Windows Servers

Windows 2012 Server Foundation, Essential, Standa…

FREE Hyper-V & VMware Virtualization Backup: FREE for Firewall.cx readers for a Limited Time! Download Now! Windows Server 2012 Editions On the 1st of August, 2012 Microsoft releas…

Network Protocols

Understanding VPN IPSec Tunnel Mode and IPSec Tra…

IPSec’s protocol objective is to provide security services for IP packets such as encrypting sensitive data, authentication, protection against replay and data confidentiality. As outlined in our IP…

Domain Name System (DNS)

The DNS Protocol - Part 2: DNS Queries & Resoluti…

This section will help you understand how the DNS queries work on the Internet and your home network. There are two ways to use the domain name system in order to resolve a host or domain name to an…

OpManager - Network Monitoring & Management

Free Webinar: Enterprise-Grade Security and Manag…

The hybrid work culture has resulted in workforces increasingly using their mobile devices for work, further adding to the complexity of ensuring security across all endpoints within organizations…

VLAN Networks

Comparing Traditional Flat & VLAN Networks

Designing and building a network is not a simple job. VLANs are no exception to this rule, in fact they require a more sophisticated approach because of the variety of protocols used to maintain and…

Domain Name System (DNS)

The DNS Protocol - Part 3: DNS Query Message Form…

This section will deal with the analysis of the DNS packets by examining how DNS messages are formatted and the options and variables they contain. To fully understand a protocol, you must understand…

TCP - UDP Protocol Analysis

TCP Header Anaylsis - Section 7: TCP Data Payload…

Finally, the last page of our incredible TCP Analysis. As most of you would expect, this section is dedicated to the DATA section that follows the TCP Header. The Data Section The following diagram…