Cabletron Systems EMM-E6 Ethernet Manual De Usuario

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. 

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.

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:

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