PuTTY is a free terminal emulation tool that’s been available for 20 years. Originally released for Microsoft Windows, this versatile remote administration tool can be used to access workstations, servers, network devices etc using various protocols such as secure shell connection (SSH), Telnet, Rlogin etc. While it continues to be popular for accessing network devices […]
[Continue reading]
In the Networking and IT world we usually design and implement networks and server infrastructure taking for granted that the hardware and applications will withstand any volume of traffic. Stress Testing a network or IT system with high volume of traffic will give us significant insights about the behavior of such systems in abnormal conditions […]
[Continue reading]
DHCP stands for Dynamic Host Configuration Protocol. Basically it’s a mechanism which assigns IP addresses to computers dynamically. Usually DHCP is a service running on a server machine in the network in order to assign dynamic IP addresses to hosts. However, Cisco Routers (and other devices such as ASA firewalls etc) can work also as […]
[Continue reading]
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 […]
[Continue reading]
As network engineers and administrators, we mostly focus on managing and configuring hardware devices such as routers, switches, firewalls, load balancers etc. We rarely deal with software management tools which are equally important in a corporate network. Without knowing the health, performance, availability and quality of your network is like running with closed eyes. Network […]
[Continue reading]
Ethernet Switches are the backbone of any network, no matter if it’s a home, office or enterprise network. Even though most of our communication nowadays is carried out wirelessly (WiFi, Mobile 3G-4G-5G etc), there ARE a lot of cases whereby network connectivity has to be implemented the “old-school” wired way. And that’s where Ethernet Switches […]
[Continue reading]
Whenever Microsoft releases security patches even for unsupported Operating Systems (such as Windows XP, Vista etc) then you must act immediately (as a company or administrator) because it’s always a serious issue. This is what happened in May 14 when Microsoft released security patches for a critical software vulnerability affecting the Remote Desktop Protocol (RDP). […]
[Continue reading]
CIDR was invented to facilitate better and more efficient allocation of IP addressing and especially IPv4 addresses which started running out pretty fast when the whole Internet accelerated its pace during the last 2-3 decades. What is Classless Inter-Domain Routing (CIDR) As you know, an IPv4 address consists of 32 bits and is represented as […]
[Continue reading]
A Cisco ASA Firewall is ideal for Broadband access connectivity to the Internet since it provides state of the art and solid network security protection. Especially for small business or home use, the ASA 5505 model is ideal for broadband ADSL access connectivity. Some ISPs provide Point to Point over Ethernet access, which is abbreviated […]
[Continue reading]
The Microsoft Point to Point Tunneling Protocol (PPTP) is used to create a Virtual Private Network (VPN) between a PPTP client and server. It is used for remote access from roaming users to connect back to their corporate network over the Internet. A PPTP client connects and authenticates to the PPTP server which assigns an […]
[Continue reading]
This article describes the security levels concept as used in the Cisco ASA firewall appliance. The following information applies to both the older 5500 series and the newer 5500-X series of appliances. A Security Level is assigned to interfaces (either physical or logical sub-interfaces) and it is basically a number from 0 to 100 designating […]
[Continue reading]
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 […]
[Continue reading]
If you have studied the OSI model with its 7 Layers that describe a communication or computer network system, you should know that the Ethernet standard lies in Layer 1 (Physical) and Layer 2 (Data-Link) of the OSI model. In this article we will focus on the physical (Layer 1) part of Ethernet, which mainly […]
[Continue reading]