Understanding the network.pdf - Back to Home

4. Don't get lost in the big picture. When examining the components related to
a process, define clear start and stop points. Every process has a beginning
and an end. Sometimes, these points are not easy to see, but they are there.
Although this seems obvious, quite often, the most obvious problems are the
hardest to spot.
5. Document, document, document. When working on a problem, especially a
performance-related one, be sure to document the results of your tests,
changes you make, and so on. Proper documentation makes it easy to
retrace steps after you have a solution. Problem resolution documentation
serves as reference material for the future, so, if a similar problem arises,
you have something to work from. Documentation also makes it easy for you
identify and undo a change you might have made trying to fix the problem
that ended up creating another problem. Many individuals also find that the
documentation process itself aids in their understanding the problem and
solution even better.
6. Mind the details. Always remember that computer networking is about
details. Each component, from a patch cord to a router, plays a role in overall
functioning of the network. A bad component, however benign, can affect
the performance of the network. Remember, when looking at a process, be
sure to identify all the elements involved. Then, when you are
troubleshooting, assume that each of the elements could be at fault and
check each element. A bad network card can bring down a whole network
segment. Often, it's the last thing anyone looks for.
Network Management Fundamentals
Before computer networks emerged, there were mainframe time-sharing systems.
These systems were standalone supercomputers that shared memory, processing,
and storage resources between a certain number of users. Users would access the
mainframe through dumb terminals that were connected to the server via serial
controllers or modems. This computing model is still used today with some UNIX
systems and client/server computing. But, large mainframe time-sharing systems
required more attention and management than most UNIX systems today.
Mainframe management was performed by systems administrators. These
administrators would monitor the mainframe's processor and memory utilization,
I/O controllers, line terminals and modems, multiplexers, channel banks, dedicated
circuits, disk, tape, and card reading systems. All these systems required constant
monitoring to continue functioning properly and effectively. What system resources
were over-utilized or under-utilized? What was the system's load average and peak
load? Were the local and remote access lines adequate to meet the access demand?
The administrators would work with system operators and analysts to resolve
system resource failures and reprovisions or add system resources.