Device virtualization is one of the most popular topics in IT industry today and Cisco has been supporting this concept in the majority of its network devices. In this article we will talk about Cisco ASA virtualization, which means multiple virtual firewalls on the same physical ASA chassis. Virtual ASA is also known as “Security […]
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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. What is Security Level A Security Level is assigned to interfaces (either physical or logical sub-interfaces) and it is basically a number from […]
[Continue reading]There are several configuration features on Cisco ASA that require some sort of password or secret-key that you need to enter. Some examples include: VPN pre-shared keys (either for site-to-site IPSEC VPN or for Remote Access). AAA server secret key when communicating with a RADIUS server. Routing Protocols keys (for OSPF, EIGRP). Secret key for […]
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As network engineers, having insights about how our network performs can save us from a lot of headaches. That’s where software tools for network diagnostics are useful for every networking professional. Pingplotter is a network diagnostic software utility used to monitor packet loss, latency, jitter etc in data packets along network paths. This tool lets […]
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One of the most asked questions from those who deployed Cisco Unified Communications Manager is how to provide external caller ID on IP phone display. CUCM does it well for internal phone lines, but what about external incoming calls? Your account managers would love seeing the name of the client calling on the IP phone. […]
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Cacti is a popular open source networking tool that is web based, and it is used both for network monitoring and graphing. In my work environment we use Cacti extensively to mainly monitor bandwidth on interfaces of switches etc. It is a complex tool to learn but very powerful. With Cacti you can poll services, […]
[Continue reading]Learning to configure your Cisco devices from the Command Line Interface (CLI) is an essential step towards your Cisco networking career. This means that you need to learn how to configure the Cisco IOS operating system which runs on routers, switches and other network devices. Acquiring this hands-on experience with the Cisco IOS CLI will […]
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On this website I have written tens of articles about enterprise level firewalls (especially Cisco ASA) but many people are interested to learn about the best hardware firewalls for home or small business networks, so this is what I’ll focus in this article. Firewalls are designed to monitor incoming and outgoing traffic, helping to keep […]
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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 […]
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Usually, in the world of network security, when we talk about Firewalls we mean the devices that help protect your computer systems and networks from attacks and provide a “wall” in front of servers and IT resources. The above concept of a “Firewall” refers to the classic network hardware firewall such as the Cisco ASA, […]
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Every host or device that is connected to a TCP/IP network must have two addresses in order to send and receive traffic on the network. These are MAC and IP addresses. Knowing the details and functionality of these two address types is essential for anyone working in networking or in I.T in general. In this […]
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Imagine the following situation: You are a network engineer and your boss or a customer wants you to build a cheap and easy solution to host a publicly accessible server (such as Webserver, Email server, VPN server etc) using only a regular Cisco router. In most network designs, you will see that the usual and […]
[Continue reading]One of the most frequent problems encountered from users of DSL internet connectivity (especially PPPoE DSL service) is when they experience incomplete connections or unreliable data transfers when they communicate with internet servers. A prominent example is when a user accesses a web site and some times it works and some times it does not. […]
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