A router’s log can save your life. Well, at the least, it can save you time and headaches when troubleshooting problems. However, in the heat of battle, old messages in the log can get in the way. After making a change to the router’s configuration, for instance, it is easier to monitor only subsequent messages […]

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.

This is an explanation of serial connection encapsulation (HDLC / PPP) and suggestions on it’s use.

Simple commands to reset BGP as a first step troubleshooting technique

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.

Ever foul up a command on a router or switch and have to sit there and wait for five minutes while it translates for the “domain” ?

You can check and customize what protocols are running through your router with nbar protocol-discovery. This gives you packet count, byte count, 5 min bit rate, and 5 min max bit rate.

Lightning produced during a thunderstorm can damage a router if a power surge occurs. This tutorial describes how to repair your router if lightning removes its EPROM cookie information.

Frame-Relay is a fundamental concept of networking. This tech-recipe will show how to configure a Frame-Relay switch and a core router within one router creating a hub-and-spoke topology.

This tech-recipe will allow you to create multiple users on a router. It is also a handy tool to find out who did what and at what time (permitting logging is on and the correct date/time is configured).