EMM-E6 Ethernet User's Guide

CHAPTER 1: INTRODUCTION
1-22 EMM-E6 User’s Guide
1.9.1 MIBs
The Management Information Bases (MIBs) are a database resident on
the EMM-E6. Objects in the information base are uniquely identified by
administratively assigned identifiers (called object identifiers or OIDs),
and can be viewed, retrieved, or changed using an SNMP packet
exchange over the network.
1.10 REVIEW OF ADDRESSING
For network devices to recognize one another, unique identifiers, referred
to as addresses, are required. The following sections are intended for
review, and do not represent a comprehensive description of network
addressing.
This section begins by discussing the two types of addressing used in
TCP/IP networks, Internet Protocol (IP) addresses and Media Access
Control (MAC) addresses. These descriptions are followed by an
overview of the process of configuring addresses in a network, including
examples of network Classes and the creation of subnets within networks.
1.10.1 MAC Addresses
The MAC address is a unique, 48-bit binary number, associated with a
specific physical connection to a network which is capable of generating
packets. Examples of devices with MAC addresses include SNMP agents
and DNI cards. MAC addresses are divided into 6 octets, and represented
in hexadecimal form such as the following:
00-00-1D-00-26-FB
All MAC addresses are administered by the IEEE and are generally
assigned at the time of manufacture, and cannot be changed. The first
three octets uniquely identify the manufacturer. Cabletron devices’ MAC
addresses all start with: 00-00-1D.
CH1Book Page 22 Wednesday, March 20, 1996 7:48 AM