Configuring the IP Helper Features
D-Link
Unified Wired and Wireless Access System
Oct. 2015
Page 283
D-Link UWS User Manual
Configuring the IP Helper Features
The IP Helper feature provides the ability for a router to forward configured UDP broadcast packets to a
particular IP address. This allows applications to reach servers on non-local subnets. This is possible even when
the application is designed to assume a server is always on a local subnet or when the application uses
broadcast packets to reach the server (with the limited broadcast address 255.255.255.255, or a network
directed broadcast address).
You can configure relay entries globally and on routing interfaces. Each relay entry maps an ingress interface
and destination UDP port number to a single IPv4 address (the helper address). Multiple relay entries may be
configured for the same interface and UDP port, in which case the relay agent relays matching packets to each
server address. Interface configuration takes priority over global configuration. If the destination UDP port for
a packet matches any entry on the ingress interface, the packet is handled according to the interface
configuration. If the packet does not match any entry on the ingress interface, the packet is handled according
to the global IP helper configuration.
IP Helper Global Configuration
Use the IP Helper Global Configuration page to globally enable the IP Helper admin mode and to configure
global relay settings on the switch.
To display the page, click
LAN > L3 Features >IP Helper > Global Configuration
in the navigation tree.
Figure 179: IP Helper Global Configuration
Table 162: IP Helper Global Configuration Fields
Field
Description
UDP Relay Mode
Select enable or disable from the pull down menu. User must enable Relay
Mode to relay any other protocols for which an IP helper address has been
configured. By Default UDP Relay Mode is disabled.
UDP Destination Port
Shows the destination UDP port ID/Port Name of UDP packets to be relayed.