Category Archives: System Networking

System Networking

How to configure a Cisco Layer 3 switch-InterVLAN Routing

On a Layer3-capable switch, the port interfaces work as Layer 2 access ports by default, but you can also configure them as “Routed Ports” which act as normal router interfaces. That is, you can assign an IP address directly on the routed port. Moreover, you can configure also a Switch Vlan Interface (SVI) with the “interface vlan” command… Read More »

How to connect the ASA 5506-X in your network for Initial Configuration

As you can see in the specs section above, there are 8x1G network interfaces and also one Management interface (Management 1/1) which belongs to the FirePOWER module. In order to deploy the device in your network and be able to start its initial configuration, connect it as following: NOTES: The Management 1/1 interface belongs to the separate FirePOWER… Read More »

Security Hardening Checklist for Cisco Routers/Switches in 10 Steps

A compromised router for example can be devastating to the whole security of the enterprise since it can be used to gain access to data, reconfigured to route traffic to other destinations, used to launch attacks to other networks, used to gain access to other internal resources etc. Therefore, hardening the network devices themselves is essential for enhancing… Read More »

HSRP Vs VRRP Vs GLBP Redundancy Protocols

HSRP Vs VRRP Vs GLBP Redundancy Protocols In this article we will discuss the similarities and differences between the 3 “First Hop Redundancy” protocols supported by Cisco devices. These are Hot Standby Router Protocol (HSRP), Virtual Router Redundancy Protocol (VRRP) and Gateway Load Balancing Protocol (GLBP). The main purpose of the above protocols is to provide redundancy to… Read More »

Cisco ASA as DHCP Server with Multiple Internal LANs

In this tutorial I will describe the configuration of an interesting network scenario that I’m sure many of you will find helpful. This scenario is applicable in many real world situations, mainly in small to medium networks. The network scenario is as follows: We have three different internal LAN networks which host user computers and other I.T infrastructure… Read More »

Cisco Switch Port Security Configuration

Introduction One of the best practices in network security is to try and stop security threats from the entry-point of a LAN network. This means that the switch can play an important role in network security since it’s the entry-point of the network. For example, port- security on Cisco switches can be used to stop MAC-flooding attacks. In… Read More »

Cisco Switch Commands Cheat Sheet

Cisco switches can be used as plug-and-play devices out of the box but they also offer an enormous amount of features. Although the main purpose of the switch is to provide inter-connectivity in Layer 2 for the connected devices of the network, there are myriad features and functionalities that can be configured on Cisco Switches. In the following… Read More »

Converting an Autonomous Access Point to Lightweight AP

Introduction In my previous article, I talked about basic configuration of a Cisco WLC controller. In that post I stated that there are two wireless architectures, Distributed and Centralized. Distributed architectures incorporate Access Points (APs) that are standalone without any central management. The APs in distributed architecture are also called Autonomous Access Points. On the other hand, Centralized… Read More »

Cisco Wireless LAN Controller Basic Configuration

Introduction Cisco introduced two types of Wireless architectures in its WiFi portfolio: Distributed Architecture. Centralized Architecture. Distributed WiFi Architecture: In Distributed Architecture all the WiFi Access Points (APs) are self-contained and called autonomous or standalone APs. Autonomous APs work individually and have to be configured and managed one by one. In this Architecture an autonomous Access Point performs… Read More »

6 Practice Lab Options for CCNA CCNP CCIE

Cisco is continuously developing new versions of its Certification Exams and adds more and more practical requirements in the syllabus. For the CCNA, you can pass the exam without much practical experience, but for the Professional and Expert Level certifications (CCNP, CCIE), having hands on experience on Cisco equipment (or labs) is required if you want to pass… Read More »

Cisco DMVPN Configuration Example

Dynamic Multipoint VPN (DMVPN) is a Cisco VPN solution used when high scalability and minimal configuration complexity is required in connecting branch offices to a central HQ Hub site. DMVPN is one of the most scalable and most efficient VPN types supported by Cisco. It is used almost exclusively with Hub-and-Spoke topologies where you want to have direct… Read More »

Basic Redistribution Between Cisco EIGRP and OSPF

The most common scenario for big enterprise networks with multiple routers is to have a single IGP routing protocol (IGP = Interior Gateway Protocol) running between the routers in order to distribute all the routing information of the network. The most common IGP routing protocols used by today’s networks are OSPF, EIGRP (Cisco proprietary) and in some cases… Read More »