D-Link DGS-1510 Series Reference Manual page 319

DGS-1510 Series Gigabit Ethernet SmartPro Switch CLI Reference Guide
Default
None.
Command Mode
Interface Configuration Mode.
Command Default Level
Level: 12.
Usage Guideline
This command is only available for VLAN interface configuration.
Use the command together with the ip forward-protocol command to control the forwarding of UDP
broadcast packets.
This command takes effect only when the received interface has an IP address assigned.
The system only forwards the packet that satisfies the following restrictions:

Destination MAC address must be broadcast address.

Destination IP address must be all-one broadcast.

Packets are IPv4 UDP packets.

IP TTL value must be greater than or equal to 2.
Example
This example shows how to add the helper address, 172.50.71.123, for VLAN 100.
Switch#configure terminal
Switch(config)#interface vlan 100
Switch(config-if)#ip helper-address 172.50.71.123
Switch(config-if)#
36-4 ip forward-protocol
This command is used to enable the forwarding of the UDP packets. Use the no form of this
command to
ip forward-protocol udp [PORT]
no ip forward-protocol udp [PORT]
Parameters
PORT
Default
By default, the commonly used application protocols are enabled.
Command Mode
Global Configuration Mode.
Command Default Level
Level: 12.
Usage Guideline
When the ip helper-address command is configured, the commonly used application protocols that
will be forwarded by default are as follows:

Trivial File Transfer Protocol (TFTP) (port 69)
(Optional) Specifies the destination port of the UDP service to be
forwarded or not.
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