While Ping is one of the best known tools for network monitoring and troubleshooting, the IOS version has a set of options that make it even more useful than the Ping you might know from your desktop. For instance, IOS … Continue reading
Sometimes it becomes necessary to build static backup routes, where a dynamically learned route is preferred, and the static route is only used if the dynamic route is lost. Common applications of this would be a WAN with a VPN … Continue reading
Cisco devices can store passwords using either a reversible (Type 7) or non-reversible (Type 4 or 5, enabled by the “secret” keyword) encryption. Reversible encryption has the ability to decrypt the stored password, which can then be compared to the … Continue reading
In this post we will take a look at the initial configuration that should be performed on a new device before the actual network configuration is performed. Most Cisco IOS devices come from the factory with a very basic default … Continue reading
In the previous post, we took a look at the basics of the OSI and TCP/IP model layers. In this post we are going to take a closer look at end to end routing of a packet, and the interaction … Continue reading
In this post, we are going to explore the OSI and TCP/IP layered model, and use some packet capture examples to illustrate the modular nature of the two models. One of the most difficult subjects for many people beginning to … Continue reading
There are a number of different ways you can implement a default route in IOS. The method you choose depends on the circumstances (routing protocol used, equipment being configured, etc.) and your design goals (such as static vs. dynamic routing.) … Continue reading
Router on a stick (or One Armed Router) is a common name for a configuration used for routing between VLANs on a single Ethernet (including Fast/Gig/10Gig) interface. This configuration uses sub-interfaces on the separate VLANs and an 802.1q or ISL … Continue reading
Switched Port Analyzer (SPAN) is a means of redirecting traffic from one switch port to another for analysis. An example would be capturing the traffic to a host with a PC running a program like Wireshark. Setting up SPAN is … Continue reading
This is good for Cisco exams, and work, if you ever need to figure out subnets on paper. To figure out the valid addresses in a subnet: Take the octet that is not 0 or 255, for example starting with … Continue reading