Build your own Cisco Terminal Server with Raspberry Pi

I have been working in Computer networking for more than 8 years now and the biggest fear I still harbor is losing access to a router by misconfiguration. During my first stint with Service Provider networks, losing access to a router or switch would mean running to the Data Centre and taking console to a router and revert the changes and this because we didn’t have console servers in our Data Centre. Our Data centre was just across the NOC so it would take less than a minute to reach the equipments. During my second stint, the Data centre was the largest in India and going to the Data Centre would take minimum of 15 minutes from the NOC. Although we had a management network connecting all networked equipments, this did not help when a router or switch was malfunctioning and the only option left was taking console. My third stint with Service Provider network had no option of running to the router as many of the PoPs were international. Few of the larger PoPs had Terminal Servers but not all had this. A question would run through anyones mind as to why someone would not provision a console server on a remote site? The primary reason is the cost. The second reason is that it does not make business sense to have a console server for a couple of routers. Continue reading

Cisco AAA and how to get Locked Out

Cisco AAA is a very important security tool to restrict access to your network equipments to only those who are Network administrators. It is an important topic for CCIE Lab and in real life as well. The problem with Network Security is that sometimes due to human error, the network gets so secured that even the Network Administrator does not get access to the equipments. To make such a mistake is very easy because not many people know what exactly goes on after enabling AAA. In this blog, we will look into ways of enabling AAA and possible ways to get out of lock out if there was a proper exit strategy. Continue reading