Specifications

PPP Interface Configuration Command Set Command Reference Guide
472 © 2003 ADTRAN, Inc. 61950860L1-35D
ip helper-address <address>
Use the ip helper-address command to configure the ADTRAN OS to forward User Datagram Protocol
(UDP) broadcast packets received on the interface. Use the no form of this command to disable forwarding
packets.
The ip helper command must be used in conjunction with the ip forward-protocol
command to configure the ADTRAN OS to forward UDP broadcast packets. See ip
forward-protocol udp <port number> on page 200 for more information.
Syntax Description
<address> Specifies the destination IP address (in dotted decimal notation) for the forwarded
UDP packets.
Default Values
By default, broadcast UDP packets are not forwarded.
Command Modes
(config-interface)# Interface Configuration Mode required (applies to all physical interfaces as well
as virtual interfaces)
Command History
Release 1.1 Command was introduced
Functional Notes
When used in conjunction with the ip forward-protocol command, the ip helper-address feature allows you
to customize which broadcast packets are forwarded.
To implement the helper address feature, assign a helper-address(es) (specifying the device that needs to
receive the broadcast traffic) to the interface closest to the host that transmits the broadcast packets. When
broadcast packets (of the specified type forwarded using the
ip forward-protocol command) are received on
the interface, they will be forwarded to the device that needs the information.
Only packets meeting the following criteria are considered eligible by the
ip helper-address feature:
1. The packet IP protocol is User Datagram Protocol (UDP).
2. Any UDP port specified using the
ip forward-protocol command.
3. The media access control (MAC) address of the frame is an all-ones broadcast address (ffff.ffff.ffff).
4. The destination IP address is broadcast defined by all ones (255.255.255.255) or a subnet broadcast (for
example, 192.33.4.251 for the 192.33.4.248/30 subnet).