Anyone who has network admin access can make changes to the running configuration on a router or switch at any time. If you are running a large IT shop or in charge of just a few folks, this feature will enable you to control the concurrent changes to your running configuration. Exclusive Configuration Change Access, […]

Sometimes, we need to transfer IOS from one router/platform to another. Other times, we can end up in Rommon> prompt because an IOS download failed of similar issue. Let’s start with a stranded router. It is strongly suggested that you get a PCMCIA memory card, insert it into a good router. From priviledged mode on

This How To discusses how to set up one Cisco Router as a PKI Server and one Cisco Router as a client. That’s right, you can set up a Cisco router as a Certificate Authority (CA) and then set up other routers as clients to use that CA to authenticate on your network.  The advantage

CAR — or “rate limiting” — is a method for managing unwanted traffic on your network and making sure it doesn’t affect important traffic. Essentially, CAR controls the bandwidth of a certain type of traffic, and an access control list (ACL) defines which traffic it controls. Once you’ve created the ACL, you can set CAR

As VoIP becomes more widely used in the enterprise, the number of voice calls traversing the enterprise WAN becomes larger and larger. Typically the use of a proper codec is implemented to reduce the amount of bandwidth a voice call requires. The most commonly used codec for WAN voice traffic is called G.729. While there

Show Version is a great command for routers, switches or PIX firewalls. Here is a look at all the things you can verify with the show version command: On Routers The version of the IOS operating system The version of the ROM bootstrap The version of the boot loader How someone last powered on the

This How To will describe the most common configuration needed for Cisco IOS to create a DHCP (IPv4) server on your switch or router. Before You Start Before you configure the DHCP address pool, you need to: •Identify DHCP options for devices where necessary, including the following: –Default boot image name –Default routers –Domain Name

This short and sweet How To explains how to configure the DHCP Client in IOS.  This is done using a single command.  Go to the interface configuration: Router(config-if)#ip address dhcp Some service providers might ask you to use a client-id and/or a hostname of their own choice. This can be done by adding the following

When a router learns multiple routes to a specific network via multiple routing processes (or routing protocols, such as RIP, RIPv2, IGRP, EIGRP, and OSPF), it installs the route with the lowest administrative distance in the routing table. Load balancing is a standard functionality of the router software, and is available across all router platforms.

The Border Gateway Protocol (BGP) allows internal and external networks or autonomous systems (AS’s) to exchange routes. BGP is a path-vector routing protocol, which simply means that its job is to exchange routing information between autonomous systems to find the most efficient path for your data to the Internet. Each BGP router connects to its

A common question folks ask is “How do you check the bandwidth utilization on a router?” It is a great question and the answer is not as easy as you would expect. There are tools that accomplish this (i.e. NetFlow and there is another mentioned at the end of this page). However, without those tools,

In this article we will define and discuss Default and Static Routes. We often see the incorrect implementation and understanding of ‘default routes’.  The default route is a “gateway of last resort.”  This special route tells computers or other routers to contact the defined next hop of the default router if they don’t have a

In this How To, we will discuss the clock setting in IOS.   When Cisco IOS boots up, the default date and time is set to March 1, 1993. You can view this using the ‘show clock’ command: cell_pe1> show clock *00:01:10.415 UTC Mon Mar 1 1993 It isn’t necessary for a router to have

Everyone knows that constantly entering commands on Cisco routers and switches can become uncomfortably repetitive. To make life somewhat easier, Cisco offers the alias command, which can help dispel part of this repetition. This is a Global Configuration command. To use it, enter the alias command and identify which privilege level you want to specify

‘Lines’ are physical async serial ports on the router (such as a terminal or modem), a virtual network connection, or another type of serial line on the router. To see which lines you have on your router, use the show line command: Cell_Router#show lineTty Typ Tx/Rx A Modem Roty AccO AccI Uses Noise Overruns Int0