Workshop

If you can’t find the manual in your shop, check the manufacturer’s Web site before buying another copy.
Some manufacturers keep the manuals on the Web as a service to their customers.
Another cool and highly informative task you can perform while in the router is to dump the routing
table. As nasty as that sounds, it just means that you’re going to list all the known routes to that router.
All the routes that apply to your organization are going to be in the route table—be sure to write down
the list of network numbers (even if the router is not connected to them) with their next hops. The next
hop will be a router that knows something more about that network, and it’s more than likely only a hop
or two away from the network. Repeat this process until you have all the networks written down with a
corresponding router identification.
By convention, most routers for a given network segment have low node numbers, starting at 1 and
working up to as many routers as there are on that segment.
Once you have an idea of which routers have which IP numbers, you should be able to start drawing a
map. Start with the router, draw the network segments off of each, and then play “connect the dots.” That
is, make correlations between which routers have common network numbers and then connect them (see
Figure 24.1).
Figure 24.1 Once you’ve laid out your network pieces like Legos, you can then snap them together
using common networks to reveal the entire picture.
Servers
If you have an idea of what the server names are, you’re one step further in the right direction. If not,
you’ll have to perform name discovery. From an operational workstation, look at the DNS configuration.
No DNS configuration? It’s possible—some sites don’t use DNS, but that’s very unlikely if the Internet
is in the picture. If you’re sure that no DNS is available, you have two options for gathering hostnames
and IP addresses of servers:
• Check the C:\Windows\HOSTS file on several functional workstations.
• Check the client configuration of several functional workstations.