Hello Alil
Documentation is an important part of networking. How to write a document however depends on the purpose of the document, who the readers will be, and what you want to express in the document.
The most common form of documentation has to do with documenting an existing network. In order to do this, you must include:
- A current network diagram that shows all of the components of the network. If it is extensively large, you may need several diagrams.
- A list of inventory of the network
- Documentation of the technologies used on the network (QoS, PoE, routing protocols, policing/shaping, VPNs)
- The services provided by the network (IP telephony, wireless, video conferencing etc)
- A record of the current configurations and IOS of the devices being used
- A record of the security parameters and feature installed
- A security policy that is to be followed by all administrators and users
There may be more information that you can add, but this is the fundamental info you should have. The point is to make the document a useful tool by a “new” administrator that comes in so that they will understand the network as it is, just from the document.
Now other types of documentation exist as well such as:
- network design documentation
- Request for Proposals (RFPs)
- Proposals
- high level network requirements description
- network cost analysis
- network risk analysis and disaster recovery
Each of these has particular information that must be included in order to provide the appropriate information to the appropriate readers.
I hope this has been helpful!
Laz