Understanding the network.pdf - Back to Home

Topology Maps
An updated network topology map is essential. This map should depict (at least) the
cabling plant and the bridges, switches, hubs, routers, and so forth on the network.
The map should indicate the physical locations of the equipment, network segments,
and device and interface addressing information. In most cases, it is easier to
develop maps that depict specific elements. For instance, one map might document
physical device interconnections, another might describe the network logically from
a protocol addressing perspective. One map might depict the equipment racks by
device and location in the computer or cable distribution room. The idea is to map
out the network in such a way that anyone can find anything by looking at the
correct map. Mapping is a common feature of many management systems, and
some are better at it than others. These systems also support automatic device
discovery and can relay status information. Though they are helpful to display and
manage the network, they are not suitable for constructing all the maps necessary
for a solid documentation set.
Device Information
Each network component should have a device information sheet. This can be an
Access or Oracle database, a set of index cards, even a set of Web pages. The idea
is to construct a uniform fact sheet about each device on the network from
end-station to routers. You should develop a universal identity scheme for all the
networked devices. This can be a hostname, internal audit, or lease serial number;
you can even use the device's MAC address. The ID needs to be unique to the device
and that one that will ideally never be duplicated or become obsolete (such as an
employee or department name). This tag is what you can use to sort through the
information. Then, for each device, you want to record some subset of the following
information:
• Universal ID
• Hostname/system name
• Installation location
• Network address(es) and supported protocols
• MAC address(es)
• Telco circuit ID(s) (if appropriate)
• Manufacture and model
• Vendor information and contact numbers
• Service contract number
• Local technical contact
• Data port assignments (what end-devices are connected to its ports)
• Software version
• Dependent or adjacent devices