Cisco Terminal Server

[Big Bad JV]

Hi All,
A couple of weeks ago on one of Joe's webinar sessions the conversation turned to how Joe was changing between the console connection on each router, was he using a serial switch box or just manually moving the console cable from router to router? We discussed using a USB to 8 way serial cable or a Cisco remote access or terminal server.

A couple of the peeps on the webinar who are quite new to the Cisco hardware were not too sure about the Cisco remote access server part of the conversation so I thought I would post up a bit of an explanation with some piccies to try to help people visualise the kit.

The 1st picture below is of a 2511 router that has 2 async modules built into the hardware, these are the two long connectors on the left of the router marked ASYNC 1-8 & ASYNC 9-16.




To use the router as a Terminal Server you would need to buy a special cable called an Octal Async cable as shown in the 2nd Picture. This cable has 8 rj45 connectors that plug directly into the Console port of all Cisco routers and switches.




To use the terminal server, you would connect directly to it via either a console cable or telnet session over the network, then use that as a connection point to all the other routers and switches that it is connected to.

Most routers, the 2511 included also have an Aux port next to the Console port that is also an rj45 connection, (tip: It’s not unknown for you to plug a console cable in here and not get a console connection to the router, causing some head scratching until you realise your mistake!) The Aux port can be used to connect an analogue modem to, so that a dialup connection from a remote site can be made and access to the routers and switches can be gained, this can be useful if the network is down and access is required to fault find. This type of connection is known as an Out Of Band (OOB) connection, as it doesn’t rely on the production network for access.

This last picture shows a NM-32A 32 port async plug in module for use in routers that have the expansion slot such as 2600 series 3600 series and newer routers.



Here's a link to the Cisco website with more info regarding how to configure the router as a terminal server.

Hope that lot helps to explain a bit about Cisco remote access servers, and encourage you to find out more.



JV