3Com Switch 4200G Configuration Guide

406 CHAPTER 48: UDP HELPER CONFIGURATION
Perform the following configuration in system view.
You must first enable UDP Helper function and then configure the UDP port with
relay function. Otherwise, error information will appear.
The parameters dns | netbios-ds | netbios-ns | tacacs | tftp | time respectively refer
to the six default ports. You can configure the default UDP port in two ways:
specifying port IDs and specifying the right parameters. For example, the udp-helper
port 53 command is equivalent to the udp-helper port dns command in function.
The default UDP ports shall not be displayed when using the display
current-configuration command. But its ID shall be displayed after its relay function
is disabled.
Configuring the Relay
Destination Server for
Broadcast Packet
You can configure up to 20 replay destination servers for a VLAN interface. If a VLAN
interface is configured with relay destination servers and UDP Helper function is
enabled at it, then the broadcast packets of a designated UDP port received at the
VLAN interface will be unicasted to the destination server.
Perform the following configuration in VLAN interface view.
The undo udp-helper server command without any parameter deletes all
destination servers configured on the interface.
By default, no relay destination server for UDP broadcast packets is configured.
Displaying and
Debugging UDP Helper
Configuration
After the above configuration, execute display command in any view to display the
running of UDP Helper destination server, and to verify the effect of the
configuration. Execute debugging command in user view to debug UDP Helper
configuration.
Table 350 Configuring a UDP port with replay function
Operation Command
Configure a UDP port with replay function udp-helper port { port | dns | netbios-ds |
netbios-ns | tacacs | tftp | time }
Remove the configuration undo udp-helper port { port | dns | netbios-ds
| netbios-ns | tacacs | tftp | time }
Table 351 Configuring the relay destination server for broadcast packet
Operation Command
Configure relay destination server for broadcast packet udp-helper server ip-address
Delete relay destination server for broadcast packet undo udp-helper server [ ip-address ]
Table 352 Displaying and debugging UDP Helper configuration
Operation Command
Display the destination server
corresponding to VLAN interface
display udp-helper server [ interface vlan-interface
vlan-id ]
Enable UDP Helper debugging debugging udp-helper { event | packet [ receive |
send ]}
Disable UDP Helper debugging undo debugging udp-helper { event | packet [
receive | send ]}