CHAPTER 1: INTRODUCTION
Page 1-16
EMME USER’S GUIDE
1.8.1 Management Information Base (MIBs)
The MIBs are a database which are resident on the network device (i.e.,
EMME). 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 or locally using MIB Navigator.
1.9
IP ADDRESSING
Each network interface or TCP/IP host is identified by a 32-bit binary
number called the IP address. This 32-bit number is divided into four
8-bit numbers called octets. Each octet is translated into its decimal
equivalent and is represented using Dotted Decimal Notation (DDN). The
DDN format is XXX.XXX.XXX.XXX.
The IP address consists of two distinct parts, the Network ID and Host ID.
There are three classes of IP addressing: Class A, B, and C.
Tables 1-2 through 1-4 describe the classes.
Table 1-2. Class A
Table 1-3. Class B
Range of Network IDs:
1 - 126.host.host.host
[1 octet for the Network ID (127
reserved)]
Binary translation:
(of first octet)
0000001 - 01111111
[first bit is always 0]
Range for the Host ID:
net.1 - 254.1 - 254.1 - 254
[3 octets for the Host ID - allows
16,777,214 hosts per network]
Range of Network
IDs:
128 -191.1 - 254.host.host
[2 octets for the Network ID]
Binary translation:
(of first octet)
1000000 - 10111111
[first bit is always 1 and second is always 0]
Range for the Host
ID:
net.net.1 - 254.1 - 254
[2 octets for the Host ID - allows 65,534 hosts
per network]
