Network Management

Imagine yourself as a network administrator, responsible for a 2000 user network. This
network reaches from California to New York, and some branches over seas. In
this situation, anything can, and usually does go wrong, but it would be your
job as a system administrator to resolve the problem with it arises as quickly
as possible. The last thing you would want is for your boss to call you up,
asking why you haven’t done anything to fix the 2 major systems that have been
down for several hours. How do you explain to him that you didn’t even know
about it? Would you even want to tell him that? So now, picture yourself in the
same situation, only this time, you were using a network monitoring program.

Sitting in front of a large screen displaying a map of the world, leaning back
gently in your chair. A gentle warning tone sounds, and looking at your display,
you see that California is now glowing a soft red in color, in place of the
green glow just moments before. You select the state of California, and it zooms
in for a closer look. You see a network diagram overview of all the computers
your company has within California. Two systems are flashing, with an X on top
of them indicating that they are experiencing problems. Tagging the two systems,
you press enter, and with a flash, the screen displays all the statitics of the
two systems, including anything they might have in common causing the problem.

Seeing that both systems are linked to the same card of a network switch, you
pick up the phone and give that branch office a call, notifying them not only
that they have a problem, but how to fix it as well. Early in the days of
computers, a central computer (called a mainframe) was connected to a bunch of
dumb terminals using a standard copper wire. Not much thought was put into how
this was done because there was only one way to do it: they were either
connected, or they weren’t. Figure 1 shows a diagram of these early systems.

If something went wrong with this type of system, it was fairly easy to
troubleshoot, the blame almost always fell on the mainframe system. Shortly
after the introduction of Personal Computers (PC), came Local Area Networks
(LANS), forever changing the way in which we look at networked systems. LANS
originally consisted of just PC’s connected into groups of computers, but soon
after, there came a need to connect those individual LANS together forming what
is known as a Wide Area Network, or WAN, the result was a complex connection of
computers joined together using various types of interfaces and protocols.

Figure 2 shows a modern day WAN. Last year, a survey of Fortune 500 companies
showed that 15% of their total computer budget, 1.6 Million dollars, was spent
on network management (Rose, 115). Because of this, much attention has focused
on two families of network management protocols: The Simple Network Management

Protocol (SNMP), which comes from a de facto standards based background of

TCP/IP communication, and the Common Management Information Protocol (CMIP),
which derives from a de jure standards-based background associated with the Open

Systems Interconnection (OSI) (Fisher, 183). In this report I will cover
advantages and disadvantages of both Common Management Information Protocol (CMIP)
and Simple Network Management Protocol (SNMP)., as well as discuss a new
protocol for the future. I will also give some good reasons supporting why I
believe that SNMP is a protocol that all network administrators should use. SNMP
is a protocol that enables a management station to configure, monitor, and
receive trap (alarm) messages from network devices. (Feit, 12). It is formally
specified in a series of related Request for Comment (RFC) documents, listed
here. RFC 1089 - SNMP over Ethernet RFC 1140 - IAB Official Protocol Standards

RFC 1147 - Tools for Monitoring and Debugging TCP/IP Internets and

Interconnected Devices [superceded by RFC 1470] RFC 1155 - Structure and

Identification of Management Information for TCP/IP based internets. RFC 1156 -

Management Information Base Network Management of TCP/IP based internets RFC

1157 - A Simple Network Management Protocol RFC 1158 - Management Information

Base Network Management of TCP/IP based internets: MIB-II RFC 1161 - SNMP over

OSI RFC 1212 - Concise MIB Definitions RFC 1213 - Management Information Base
for Network Management of TCP/IP-based internets: MIB-II RFC 1215 - A Convention
for Defining Traps for use with the SNMP RFC 1298 - SNMP over IPX (SNMP, Part 1
of 2, I.1.) The