Configuring Udp Helper; Establishing The Configuration Task; Enabling The Udp Helper Function - Huawei S9300 Configuration Manual

S9300&S9300E Terabit Routing Switch
Configuration Guide - IP Service
The UDP helper function cannot be used to send DHCP messages, that is, the number of the
UDP port cannot be 67 or 68. do not support the UDP helper function.To forward Dynamic Host
Configuration Protocol (DHCP) messages, you need to

7.3 Configuring UDP Helper

This section describes how to configure UDP helper to forward IP broadcast packets of a
specified UDP port.

7.3.1 Establishing the Configuration Task

Applicable Environment
When an S9300&S9300E on a network needs to obtain network configurations or query the
name of another device by sending broadcast packets, you can enable the UDP helper function
if the S9300&S9300E and the device to be queried are in different broadcast domains.
Pre-configuration Tasks
Before configuring the UDP helper function, complete the following task:
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Data Preparation
To configure the UDP helper function, you need the following data.
No.
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7.3.2 Enabling the UDP Helper Function

Context
After the UDP Helper function is enabled, the S9300&S9300E checks the destination UDP port
of the received packet and determines whether to relay the packet. Then the S9300&S9300E
performs the operations as follows:
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Issue 01 (2012-03-15)
Configuring a reachable route between the S9300&S9300E and the server
If the destination UDP port number of packets matches the UDP port number on which
packets need to be forwarded and the destination MAC address is the broadcast MAC
address, the S9300&S9300E changes the destination IP address in the IP packet header and
sends them to a specified destination server.
If the destination UDP port number of packets does not match the UDP port number on
which packets need to be forwarded, the S9300&S9300E discards them.
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7 UDP Helper Configuration
enable the DHCP relay
Data
UDP port on which packets are forwarded
VLANIF interface and IP address of the
destination server that sends packets of UDP
ports
function.
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