How do you document your Cisco configurations?

How do you document your Cisco configurations?

• How much / what kind of information do you include in the description field (connects to, circuit ID, device information, etc.)?
• Do you use any automated tools, such as Rancid, to do automatic backups and revision control?
• How do you provide additional documentation details that won't fit in the description field? Preferably with some sophistication that allows some ability to hide details or have a dynamic view (e.g. Visio maps can quickly become overwhelming).

Solution 1:

Couple of different ways. Mainly I do NOT rely on static documentation for current info. It's never "current" due to the nature of a network. Let it be as self-documenting as possible.

1. Generic Design Diagram - Keep the backbone design in Visio... i.e. connections between buildings, the major routers, etc. As a general rule, if changing it involves a dude on a backhoe, go ahead and put it in Visio, print it out on a plotter, hang it on the wall, etc.
2. Descriptions - Cisco provides the means to assign descriptions to each interface. Use them with a naming convention that makes sense for your network. i.e. "Conn-To-Bldg-2-Fiber"; If in doubt, you can never put too much info in the description field.
3. Active Management Tools (or Configuration Management DB) - Use SNMP extensively to query for information when you need it. If you have lots of IP addresses that you need to manually keep track of, SolarWinds' free tool does a great job. There are a number of other tools on the market that can help with this.
4. Monitoring Tools - Establish monitoring tools, if you don't have them already. If you need more information about each device, this is a great place to put it, because, for example, if you change the address of the device, you will by necessity have to update the monitoring tool or it will keep yelling at you. :)

Solution 2:

I just use subversion and Dia.

I don't know about Visio, but Dia supports layers, if you can use layers with Visio then that might help manage the diagram from becoming overwhelming. For instance, you could make a layer for all the 'connections', another layer for the interfaces, etc. And then show and hide the layers to see the information you are interested in.

Solution 3:

The answer, as always, is "it depends." If you have a small number of routers that don't change very often then document everything, use Visio or whatever.

On the other hand, if you have a large number of routers with regularly changing configurations (a typical service provider) then you should create high level network diagrams with key interfaces shown clearly. A configuration management tool like rancid is absolutely essential in a busy service provider environment and is easy to set up so a worthwhile investment of time anywhere IMO.