Post Views: 3,237 This one is short and sweet. Is your traceroute responding with “* * *”, or did you enter 1000000000 for the number of extended pings? Easy – simply type CTRL-SHIFT-6 to break the process. That is the Control Key (hold down), the Shift Key (also hold down) and the “6” key – […]
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Post Views: 1,511 The Virtual Router Redundancy Protocol (VRRP) is a computer networking protocol that provides for automatic assignment of available Internet Protocol (IP) routers to participating hosts. This increases the availability and reliability of routing paths via automatic default gateway selections on an IP subnetwork. See RFC 5798. VRRP provides information on the state
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Post Views: 2,112 How many times have I received a router that has no operating system on it? Way to many!! You turn on the router and it comes up in ROM Monitor mode (ROMMON). There is a way to get the operating system on the router from ROMMON. Below, I have documented the procedure.
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Post Views: 2,192 Monitoring the traffic pattern on a network are essential in today’s network. If network administrators do stay on top of the traffic patterns, they may make crucial mistakes in network provisioning or design. With the Internet in a constant state of flux as new and hot applications emerge, this task becomes even
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Post Views: 2,254 ACL’s’ are vital to networking today. Everyone uses them, and proper usage is imperative. Besides being difficult to use at times, the penalty for an ACL mistake is huge. In one swift swoop, you could incorrectly permit malicious attackers onto your network or incorrectly deny all valid users from your network. Either
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Post Views: 1,440 What is AAA? It stands for Authentication, Authorization, and Accounting. When it comes to network security, AAA is one of many features a network manager may use. Here is what each of these are used for and why you should care: Why every network admin should care about AAA Besides passing certification
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Post Views: 1,771 As we said in our basic ACL How To, ACL’s’ are vital to networking today. Everyone uses them, and proper usage is imperative. In this How To, we are going a little deeper into two ACL types: Intrastructure and Transit. We will discuss the two with examples and you will clearly understand
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Post Views: 1,355 What is NBAR? NBAR is a powerful packet filtering/identification/firewall that you may already have installed on your Cisco router. For a list of what NBAR can detect look here. NBAR is also what we call Cisco’s “autopilot” for QoS. It has been in IOS since ver. 12.0 and has been continually updated
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Post Views: 2,136 The order of operations is hard coded into Cisco IOS and tells the router how to process traffic according to the configuration of different router functions and features. While we cant’ make you think like a router, it is likely you have already picked up on some of these. When configuring features
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Post Views: 1,468 This How To explains the fundamentals of configuring EIGRP. EIGRP is an advanced distance-vector routing protocol that is used on a computer network to help automate routing decisions and configuration. The protocol was designed by Cisco Systems as a proprietary protocol, available only on Cisco routers, but Cisco converted it to an
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Post Views: 1,594 This How To explains how to fix an annoying default behavior on Cisco IOS. Mistype a command on a Cisco router and the router thinks you just typed a hostname. This is often an annoying problem. For example: Router#shwoTranslating “shwo”…domain server (10.1.1.1) % Unknown command or computer name, or unable to find
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Post Views: 1,968 What happens if there is a system or user on a VLAN that is infected by malware or is deliberately running a scanning program? This can cause a massive amount of entries in the CAM Table of the switch. Think of the CAM table as the MAC address table. There is a
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Post Views: 2,404 When a router has to forward a packet, it looks in its routing table to match as many bits as possible of the destination address to a route in its routing table. This is known as longest match routing. Once a match is found, the router forward the packet to the next
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Post Views: 1,710 Part of the answer is in your question: it is a protocol, and it stands for Locator/ID Separation Protocol. The use of LISP is targeted at deployment of virtual systems, and the movement/management of those systems/resources (such as Virtual Machines) across networks to other places such as other data centers. LISP really
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Post Views: 1,746 Great questions! I think the best way to answer the question is to describe what each one is. I will start with Cisco ONE. Cisco ONE ONE stands for “Open Network Environment”. The idea is to allow programmability of the network and the network elements. This allows for consistency across both physical
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