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

S9300&S9300E Terabit Routing Switch
Configuration Guide - IP Service

7.1 Introduction to UDP Helper

This section describes the principle of UDP helper.
The S9300&S9300E on a network needs to obtain network configurations or query the name of
another device by sending broadcast packets. The S9300&S9300E, however, cannot obtain the
required information if the S9300&S9300E and the server or the device to be queried are in
different broadcast domains.
To address the preceding problem, the S9300&S9300E provides the UDP helper function.
Through the UDP helper function, the S9300&S9300E can convert broadcast packets on a
specified User Datagram Protocol (UDP) port into unicast packets to be sent to a specified
destination server, or forward broadcast packets on a subnet to another subnet.
7.2 UDP Helper Features Supported by the S9300&S9300E
This section describes the UDP Helper features supported by the S9300&S9300E.
After the UDP helper function is enabled on the S9300&S9300E, the S9300&S9300E forwards
broadcast packets of six default UDP ports to corresponding destination servers in unicast mode.
Other UDP ports must be configured manually.
Table 7-1
Table 7-1 Lists of default UDP ports on which packets are forwarded after the UDP helper
function is enabled
Protocol
Trivial File Transfer
Protocol (TFTP)
Domain Name
System (DNS)
Time Service
NetBIOS Name
Service (NetBIOS-
NS)
NetBIOS Datagram
Service (NetBIOS-
DS)
Terminal Access
Controller Access
Control System
(TACACS)
Issue 01 (2012-03-15)
lists the default ports.
UDP Port Number
69
53
37
137
138
49
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
7 UDP Helper Configuration
133