Introduction To Dhcp; Dhcp Features Supported By The S9300&S9300E - Huawei S9300 Configuration Manual

S9300&S9300E Terabit Routing Switch
Configuration Guide - IP Service

3.1 Introduction to DHCP

Dynamic Host Configuration Protocol (DHCP) enables a client to dynamically obtain a valid IP
address.
Overview
Network scales and complexity grow fast, so the network configurations become increasingly
complicated. For example, the locations of hosts such as portable computers and wireless
network terminals frequently change, and the number of hosts often exceeds the number of
available IP addresses. The DHCP is developed to solve the preceding problems.
DHCP works in the client/server model. A DHCP client requests the DHCP server for
configurations, and the DHCP server sends the configurations to the client.
DHCP of earlier versions requires that the DHCP clients and DHCP server be in the same
network segment; therefore, each network segment needs a DHCP server. This wastes resources.
DHCP relay achieves address allocation between network segments.
Definition
DHCP server
A DHCP server allocates IP addresses to clients. A client sends a packet to the server to request
for configurations such as the IP address, subnet mask, and default gateway. After receiving the
packet, the server replies with a packet carrying the corresponding configurations according to
policies. Both the Request and Reply packets are encapsulated in UDP packets.
DHCP relay agent
A DHCP relay agent transparently transmits DHCP broadcast packets between the DHCP clients
and DHCP server that are on different network segments.
3.2 DHCP Features Supported by the S9300&S9300E
The S9300&S9300E can be used as a DHCP server or a DHCP relay agent.
Table 3-1
Table 3-1 DHCP usage scenarios
Usage
DHCP server based on the global address
pool
DHCP server based on the interface address
pool
DHCP relay agent
Issue 01 (2012-03-15)
describes the DHCP usage scenarios where the S9300&S9300E is used.
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Copyright © Huawei Technologies Co., Ltd.
Scenario
The DHCP clients and DHCP server are on
the same network segment or on different
network segments.
The DHCP clients and DHCP server are on
the same network segment.
The DHCP clients and DHCP server are
different network segments.
3 DHCP Configuration
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