Chapter 1 Udp Helper Configuration; Introduction To Udp Helper; Configuring Udp Helper - H3C S5500-EI series Operation Manual

Operation Manual – UDP Helper
H3C S5500-EI Series Ethernet Switches

Chapter 1 UDP Helper Configuration

When configuring UDP Helper, go to these sections for information you are interested
in:

Introduction to UDP Helper

Configuring UDP Helper

Displaying and Maintaining UDP Helper
UDP Helper Configuration Example
1.1 Introduction to UDP Helper
Sometimes, a host needs to forward broadcasts to obtain network configuration
information or request the names of other devices on the network. However, if the
server or the device to be requested is located in another broadcast domain, the host
cannot obtain such information through broadcast.
To solve this problem, the device provides the UDP Helper function to relay specified
UDP packets. In other words, UDP Helper functions as a relay agent that converts UDP
broadcast packets into unicast packets and forwards them to a specified destination
server.
With UDP Helper enabled, the 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.
1.2 Configuring UDP Helper
Follow these steps to configure UDP Helper:
Enter system view
Enable UDP Helper
Enable the forwarding of
packets with the specified
UDP destination port
number(s)
Enter VLAN interface view
To do...
system-view
udp-helper enable
udp-helper port
{ port-number | dns |
netbios-ds | netbios-ns |
tacacs | tftp | time }
interface Vlan-interface
vlan-id
Chapter 1 UDP Helper Configuration
Use the command...
1-1
Remarks
—
Required
Disabled by default.
Required
By default, no UDP port
number is specified.
—