Messages logged by a router can make troubleshooting problems substantially easier. However, the default size of most Cisco routers is 4096 bytes which typically accommodates fewer than 60 messages. While this may help in many situations, adding some additional space can save the day when a router generates frequent error messages as when an interface […]

When replacing a faulty router that is not completely dead, it may be possible to copy the startup configuration to the removable flash memory and swap the flash to get the new router up and configured in as short a time as possible. Without this procedure, manually copying the old configuration to the new router […]

Every active interface on a Cisco router to be used with IP requires an IP address be assigned to it. This short tech-recipe describes how to set an interface’s IP address.

I found an ancient 2500 series router today and had to go through a password recovery. The rommon version was earlier than any I had seen before. The help functionality was very lean. Here is how to set the confreg for these older models.

The following tech recipe explains MD5 authentication for RIPv2 routers.

This tech-recipe describes configuring OSPF authentication to prevent unauthorized routing updates.

To help prevent unauthorized routing updates, EIGRP can be configured to authenticate peers. The following tech-recipe explains how this is done.

ODR is used to allow hub routers to accept prefix information distributed via Cisco Discovery Protocol (CDP) from spoke routers. This tutorial explains configuring ODR.

Faraway routers can be safely configured by using a reload command first. If the router becomes unreachable as a result of a typo or other misconfiguration, you need only wait, and the router will reload itself to the saved configuration permitting you to try, try again.

ATM is growing in popularity as a wide-area network (WAN) medium. ATM offers small cell size and strict quality of service, allowing voice, video, and data to coexist.

Cisco VWIC cards need configuration before their serial ports will appear in the interface list. Once the VWIC is configured, HDLC, frame relay, or ATM with an AIM processor can be configured.

Frame relay is an attractive choice for wide-area network (WAN) connections. It offers simple configuration and allows one telco circuit to connect many locations. The following tutorial decribes configuring a frame relay.