Network Protocol Operation; Configure Ip Address; Subnet And Mask - 3Com 7700 Configuration Manual

4

Configure IP Address

Subnet and Mask

N
ETWORK
This chapter covers the following topics:
Configure IP Address
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ARP Configuration
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DHCP Relay
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IP Performance
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IP address is a 32-bit address represented by four octets. IP addresses are divided
into five classes: A, B, C, D and E. The octets are set according to the first a few
bits of the first octet.
The rule for IP address classification is described as follows:
Class A addresses are identified with the first bit of the first octet being 0.
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Class B addresses are identified with the first bit of the first octet being 10.
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Class C addresses are identified with the first bit of the first octet being 110.
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Class D addresses are identified with the first bit of the first octet being 1110.
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Class E addresses are identified with the first bit of the first octet being 11110.
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Addresses of Classes A, B and C are unicast addresses. The Class D addresses are
multicast addresses and Class E addresses are reserved for future uses.
At present, IP addresses are mostly of Class A, Class B and Class C. IP addresses of
Classes A, B and C are composed of two parts: network ID and host ID. Their
network ID lengths are different.
Class A IP addresses use only the first octet to indicate the network ID.
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Class B IP addresses use the first two octets to indicate the network ID.
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Class C IP addresses use the first three octets to indicate the network ID.
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At most, there are: 28 =128 Class A addresses, 216=16384 Class B addresses and
224=2,097,152 Class C addresses.
The IP address is in dotted decimal format. Each IP address contains 4 integers in
dotted decimal notation. Each integer corresponds to one byte,
e.g.,10.110.50.101.
IP protocol allocates one IP address for each network interface. Multiple IP
addresses should can only be allocated to a device which has multiple network
interfaces. IP addresses on a device with multiple interfaces have no relationship
among themselves. One IP address cannot uniquely identify one device.
P
ROTOCOL
O
PERATION