H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 108)

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UDP helper configuration
This chapter includes these sections:
• Introduction to UDP helper
• Configuring UDP
• Displaying and maintaining UDP helper
• UDP helper configuration example
NOTE:
•
The term "switch" or "device" in this chapter refers to the switching engine on a WX3000E wireless
switch.
• The WX3000E series comprises WX3024E and WX3010E wireless switches.
• The port numbers in this chapter are for illustration only.
• UDP helper can be configured on VLAN interfaces only.
Introduction to UDP helper
UDP helper functions as a relay agent that converts UDP broadcast packets into unicast packets and
forwards them to a specified destination server. This is helpful when a host cannot obtain network
configuration information or request device names through broadcasting because the server or host to be
requested is located on another broadcast domain.
With UDP helper enabled, a device decides whether to forward a received UDP broadcast packet
according to the UDP destination port number of the packet.
• If the destination port number of the packet matches the one pre-configured on the device, the
device modifies the destination IP address in the IP header, and then sends the packet to the
specified destination server.
• If not, the device sends the packet to the upper layer protocol for processing.
Configuring UDP helper
Follow these steps to configure UDP helper:
To do… Use the command… Remarks
Enter system view system-view —
Enable UDP helper udp-helper enable
Required
Disabled by default.
Enable the forwarding of packets
with the specified UDP destination
port number(s)
udp-helper port { port-number | dns |
netbios-ds | netbios-ns | tacacs | tftp
| time }
Required
No UDP port number is specified
by default.
Enter interface view
interface interface-type
interface-number
—