What you need to know about Cisco IOS access-list filtering

Subscribe to Cisco Routers and Switches Get Cisco Routers and Switches Alerts

Cisco IOS ACLs are difficult to use. You can unwittingly create havoc on your network if you don't know some of the basic rules. David Davis focuses on the role of ACLs in packet filtering and tells you what you must know in order to make them work for you. [Read More] Posted By: David Davis on 06/05/2008 @ 08:02:47 AM in Network Administrator

View all Special Reports More on Cisco Routers and Switches

Exploring entry-level options for using VoIP

In an era of slashed IT budgets, David Davis looks at several lower-cost and entry level options of implementing VoIP, including those from Cisco. [Read More] Posted By: David Davis on 12/18/2008 @ 11:01:15 AM in Network Administrator

The 10 Cisco IOS Router file management commands you must know

David Davis goes over the Cisco IOS commands you must know to manipulate files on your Cisco router flash, nvram, or other filesystems, allowing you to back up your configuration, upgrade your router, or just maintain the IOS file system. [Read More] Posted By: David Davis on 12/12/2008 @ 06:00:05 AM in Network Administrator

10 dumb things you can do to your Cisco router and how to fix them

David Davis points out the dumb things you can do to mess up your Cisco router and how to fix them. He also lists some important resources for each step to give you even more detailed instructions. [Read More] Posted By: David Davis on 12/04/2008 @ 01:24:18 PM in Network Administrator

Filter Web content with Cisco IOS routers

Today, filtering content at many companies isn't just optional; it is a legal requirement and something you have to do to prevent employees from getting into trouble. David Davis explains how Cisco IOS routers can filter Web content with the help of outside services. [Read More] Posted By: David Davis on 11/21/2008 @ 06:00:29 AM in Network Administrator

Check out the most powerful Cisco routers ever made

They may not be appropriate for your home, office, or even your enterprise, but some of the most powerful routers in the world make it possible for you to surf the Web and send e-mail around the globe. David Davis introduces you to Cisco's lineup of service-provider routers. [Read More] Posted By: David Davis on 11/14/2008 @ 06:00:35 AM in Network Administrator

Prevent router changes from multiple users with Cisco IOS configuration lock

If multiple network admins were to connect to a router and modify the configuration at the same time, changes could be lost or only partially implemented, resulting in network downtime. David Davis introduces a new Cisco feature called IOS configuration lock that helps prevent such clashes. [Read More] Posted By: David Davis on 10/30/2008 @ 10:02:16 AM in Network Administrator

Configure Cisco routers to save core dumps for troubleshooting crashes

David Davis tells you what you need to know about saving core dump information from your Cisco router in the event of a router crash. [Read More] Posted By: David Davis on 10/24/2008 @ 06:00:07 AM in Network Administrator

Use extended ping and extended traceroute to better troubleshoot your Cisco network

Every admin is familiar with the well-known troubleshooting commands ping and traceroute. David Davis shows you how to use these commands in their extended versions to become an expert at troubleshooting your Cisco network. [Read More] Posted By: David Davis on 10/17/2008 @ 06:00:23 AM in Network Administrator

How can PacketTrap Perspective help you manage your Cisco network?

David Davis explains how the new network management platform, PacketTrap Perspective, can help you better manage your Cisco network. [Read More] Posted By: David Davis on 10/09/2008 @ 11:10:20 AM in Network Administrator

Manage network broadcasts on Cisco switches using storm control

It's important to protect your organization's LAN from broadcast storms, which can cause network slowdowns if they become severe. David Davis explains how you can easily and quickly defend your network by configuring storm control on each Cisco switch interface. [Read More] Posted By: David Davis on 10/03/2008 @ 06:00:44 AM in Network Administrator

How will the Cisco Nexus 1000V change your job role?

Announced at VMworld 2008, Cisco will soon release a new software switch, running the Cisco IOS, that will run on x86 systems using VMware ESX Server. David Davis tells you how this new virtual Cisco switch could help you and how it will change the administration of Cisco networks. [Read More] Posted By: David Davis on 09/26/2008 @ 06:00:58 AM in Network Administrator

What is AAA and how do you configure it in the Cisco IOS?

You probably use Authentication, Authorization, and Accounting (AAA), in some form, every day. But what is AAA in terms of network security? David Davis tells you what you need to know about AAA and the basic configuration for it in the Cisco IOS. [Read More] Posted By: David Davis on 09/19/2008 @ 06:00:37 AM in Network Administrator

Increase network bandwidth using Cisco's EtherChannel

David Davis explains how to configure EtherChannel to increase your bandwidth and provide redundancy on a Cisco network. [Read More] Posted By: David Davis on 09/12/2008 @ 06:00:11 AM in Network Administrator

Virtual Router Redundancy Protocol (VRRP) makes your network more reliable

David Davis introduces the Virtual Router Redundancy Protocol (VRRP), which enables you to set up a group of routers as a default gateway router for backup or redundancy purposes. [Read More] Posted By: David Davis on 09/05/2008 @ 06:00:50 AM in Network Administrator

Learn what you need to know about cabling and Cisco networking

When your routers and switches are working as expected, you don't think too much about cables. But when you're troubleshooting a problem or making a change, cabling plays a more important role. David Davis goes over some cabling basics and discusses Cisco console port cabling. [Read More] Posted By: David Davis on 08/29/2008 @ 06:00:43 AM in Network Administrator

Learn how PCI affects Cisco network configuration

If your business accepts credit cards and you haven't yet had to get tough with your network security, you will eventually. David Davis explains how the PCI data security standards affect your Cisco router and switch security configuration. [Read More] Posted By: David Davis on 08/22/2008 @ 06:00:43 AM in Network Administrator

How can Cisco Automatic Signature Extraction prevent zero-day virus attacks?

The Cisco IOS is powerful and already running on your routers. You would think that it could play a part in this virus detection and prevention, right? Luckily, it can. David Davis explains how it works. [Read More] Posted By: David Davis on 08/15/2008 @ 06:00:04 AM in Network Administrator

Roll back changes on your Cisco router with this command

Have you ever made changes to your Cisco router or switch and then needed to remove them? There are several ways to do this, but which is the safest and easiest method? Rebooting the router or switch isn't the answer. In fact, a simple command is a much better bet. [Read More] Posted By: David Davis on 08/08/2008 @ 06:00:52 AM in Network Administrator

Monitor Cisco routers and switches using the IOS environment command

How do you know if your remote router and switches are being cooled properly? Are the fans working? David Davis tells you how to see the environmental status of your Cisco routers and switches and how to be alerted when there is a hardware problem. [Read More] Posted By: David Davis on 08/01/2008 @ 06:00:20 AM in Network Administrator

Get to know the Cisco IOS Feature Navigator

David Davis tells you how the Cisco IOS Feature Navigator can help you find the information you need, including what features your current IOS image has, the differences between two IOS images, and whether your router can support the latest IOS. [Read More] Posted By: David Davis on 07/24/2008 @ 06:00:35 AM in Network Administrator

How to view Cisco IOS ACL statistics

David Davis shows you how to view ACL statistics and, with the help of a new feature in the Cisco IOS, how you can view these usage statistics per interface and per direction. [Read More] Posted By: David Davis on 07/17/2008 @ 06:00:08 AM in Network Administrator

Cisco administration 101: Monitor network traffic with NetFlow

David Davis introduces you to NetFlow, a standard for network traffic analysis. He shows you how you can use it to see the utilization on a router -- as well as the traffic that's causing the utilization. [Read More] Posted By: David Davis on 07/16/2008 @ 07:00:27 AM in Network Administrator

What you need to know about Cisco's new CCNA specializations

Cisco's most popular certification is the Cisco Certified Network Associate (CCNA). Recently, Cisco announced a number of new specialized CCNA certifications. What are these specializations, and should you be considering one? David Davis discusses each of these new certifications in more detail. [Read More] Posted By: David Davis on 07/10/2008 @ 11:22:23 AM in Network Administrator

Configuring the Cisco 851W or 871W: Standard IOS

This tutorial by George Ou and Justin James shows you how to set up an advanced SOHO configuration for the Cisco 851W router. [Read More] Posted By: George Ou on 07/03/2008 @ 12:54:28 PM in Network Administrator

How to properly secure your Cisco router with passwords

Some of the worst security breaches occur because people neglect basic security measures. David Davis discusses the importance of maintaining proper passwords on your router, explains the three modes for the Cisco IOS, and shows you how to configure the five main passwords that protect your network. [Read More] Posted By: David Davis on 06/26/2008 @ 09:26:38 AM in Network Administrator

Understand the levels of privilege in the Cisco IOS

The Cisco IOS actually offers 16 different privilege levels. David Davis discusses these different levels and introduces you to the main commands you'll need to configure these privileges. [Read More] Posted By: David Davis on 06/20/2008 @ 06:46:06 AM in Network Administrator

Cisco Administration 101: Understand the OSI model to become a better Cisco troubleshooter

David Davis explains how the seven layers of the OSI Model can help you as a Cisco administrator. Get a brief overview of the OSI model and learn why it is more than just a textbook concept -- understanding it will help you every day of your career. [Read More] Posted By: David Davis on 06/20/2008 @ 06:44:21 AM in Network Administrator

10 commands you should master when working with the Cisco IOS

Becoming proficient with the Cisco IOS means learning some essential commands. This quick reference describes 10 commands you'll need to rely on when handling various configuration and troubleshooting tasks. [Read More] Posted By: David Davis on 06/13/2008 @ 06:33:11 AM in Network Administrator

Troubleshoot Cisco routers and switches using the debug commands

David Davis shows you how to get to the bottom of router and switch issues with Cisco's debug commands. Debug can give you a lot of detailed troubleshooting information, but watch out for the debug mistakes that can seriously affect your network. [Read More] Posted By: David Davis on 06/12/2008 @ 09:59:56 AM in Network Administrator