3Com Switch 4500 26-Port User Manual

UDP Helper Configuration 97
UDP Helper
Configuration
UDP Helper configuration includes:
■ Enabling/Disabling UDP Helper Function
■ Configuring UDP Port with Replay Function
■ Configuring the Relay Destination Server for Broadcast Packet
Enabling/Disabling UDP Helper Function
When the UDP Helper function is enabled, you can configure the UDP ports where
UDP function is required and the relay function is enabled at UDP ports 69, 53, 37,
137, 138, and 49. When the function is disabled, the relay function configured at
all UDP ports, including the default six ports, is disabled.
Perform the following configuration in System View.
By default, the UDP Helper function is disabled.
Configuring UDP Port with Replay Function
When the UDP relay function is enabled, by default the system forwards the
broadcast packets on the UDP ports listed in
Table 93. You can configure up to
256 UDP ports with the relay function.
Perform the following configuration in System View.
Note that:
■ You must first enable the UDP Helper function and then configure the UDP
port with the relay function. Otherwise, error information will appear.
■ The parameters dns, netbios-ds, netbios-ns, tacacs, tftp and time
respectively refer to the six default ports. You can configure the default UDP
port in two ways: specifying port IDs and specifying the correct parameters.
Tab le 92 Enabling/Disabling UDP Helper function
Operation Command
Enable UDP Helper function udp-helper enable
Disable UDP Helper function undo udp-helper enable
Tab le 93 Default UDP Ports List
Protocol UDP port ID
Trivial File Transfer Protocol (TFTP) 69
Domain Name System (DNS) 53
Time service 37
NetBIOS Name Service (NetBIOS-NS) 137
NetBIOS Datagram Service (NetBIOS-DS) 138
Terminal Access Controller Access Control System (TACACS) 49
Tab le 94 Configuring UDP Port with Replay Function
Operation Command
Configure 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 }

3Com Switch 4500 26-Port Specifications

General

Brand	3Com
Model	Switch 4500 26-Port
Category	Switch
Language	English