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Cisco Services & Technologies
One of the most difficult things for people who are starting out in a networking career is getting their hands on the equipment. Whether you are stud…
Cisco Routers
Generic Routing Encapsulation (GRE) is a tunneling protocol developed by Cisco that allows the encapsulation of a wide variety of network layer proto…
Cisco CallManager-CCME
Our previous article, Cisco CallManager Express Basic Concepts - Part 1 covered the very basic concepts of CCME and its operation. This article conti…
Cisco CallManager-CCME
Firewall.cx readers can now download free Cisco firmware files for all Cisco IP Phones & Cisco ATA devices. Our new Cisco IP Phone & ATA Firm…

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Data Center Articles:

It’s a reality – Australia now has its own Official Cisco Data Center User Group (DCUG) and it’s growing fast! Originally inspired by Cisco Champions…
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 usi…
This article introduces the Cisco Nexus product family (Nexus 9000, Nexus 7000, Nexus 5000, Nexus 3000, Nexus 2000, Nexus 1000V and MDS 9000). We exp…
The Cisco NX-OS checkpoint feature provides the capability to capture at any time a snapshot (backup) of the Cisco Nexus configuration…

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Cisco Switches
This article provides in-depth analysis of DHCP Option 82 (DHCP Relay Agent) which is one of the +180 DHCP Options available to the DHCP protocol and used…
Cisco Switches
Cisco announces the end-of-sale and end-of-life dates for the Cisco Catalyst 3750G, 3560G, 3750-E, and 3560-E Series Switches. The last day to order the a…
Cisco Switches
In previous articles, we showed how it is possible to configure a Cisco router or Catalyst switch to provide DHCP server services to network clients. Ever…
Cisco Switches
This article covers popular Layer 2 & Layer 3 network attacks with a focus on DHCP Starvation Attacks, Man-in-the-Middle attacks, unintentional rogue…

Cisco Firewalls
Cisco’s Adaptive Security Appliance (ASA) Firewalls are one of the most popular and proven security solutions in the industry. Since the introduction of t…
Cisco Firewalls
In late 2014, Cisco announced the new licensing model for the latest AnyConnect Secure Mobility client v4.x. With this new version, Cisco introduced a num…
Cisco Firewalls
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 ma…
Cisco Firewalls
This article examines the concept of NAT Reflection, also known as NAT Loopback or Hairpinning, and shows how to configure a Cisco ASA Firewall running AS…

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SASE & SD-WAN Networks
The digital transformation is pushing applications to the cloud, the 2020-2022 pandemic shifted employees to work from home, and the number of resulting n…
SASE & SD-WAN Networks
SD-WAN is the answer for enterprises and organizations seeking to consolidate network functions and services while at the same time simplify their WAN inf…
Palo Alto Networks
Our previous article explained how Palo Alto Firewalls make use of Security Zones to process and enforce security policies. This article will explain the…
Virtualization & VM Backup
In this article, we'll show you how to deal with VMs which are reported to have an Invalid Status as shown in the screenshot below. This is a common…