C613-50170-01 Rev B
Command Reference for x510 Series
790
AlliedWare Plus™ Operating System - Version 5.4.7-1.x
IP A
DDRESSING
AND
P
ROTOCOL
C
OMMANDS
IP
HELPER
-
ADDRESS
ip helper-address
Overview
This command adds a forwarding destination address for IP Helper to enable
forwarding of User Datagram Protocol (UDP) broadcasts on an interface.
Use the
no
variant of this command to disable the forwarding of broadcast packets
to specific addresses.
Syntax
ip helper-address <
ip-addr
>
no ip helper-address <
ip-addr
>
Default
The destination address for the
ip helper-address
command is not configured by
default.
Mode
Interface Configuration for a VLAN interface or a local loopback interface.
Usage
Combined with the
command in global configuration
mode, the
ip helper-address
command in interface mode allows control of which
protocols (destination port numbers) are forwarded. The
ip forward-protocol
udp
command configures protocols for forwarding, and the
ip helper-address
command configures the destination address(es).
The destination address can be a unicast address or a subnet broadcast address.
The UDP destination port is configured separately with the
ip forward-protocol
udp
command. If multiple destination addresses are registered then UDP packets
are forwarded to each IP address added to an IP Helper. Up to 32 destination
addresses may be added using IP Helper.
The device will only forward the types of UDP broadcast packets that are specified
by the
ip forward-protocol
command(s). The device does not forward any other
UDP packet types by default.
The
ip helper-address
command does not support BOOTP / DHCP Relay. The
command must be used instead. For this reason, you may not
configure UDP ports 67 and 68 with the
ip forward-protocol
command.
IP Feature Overview and Configuration Guide
for more information about
DHCP Relay.
Examples
The following example defines IPv4 address 192.168.1.100 as an IP Helper
destination address to which to forward UDP broadcasts received on vlan2:
awplus#
configure terminal
awplus(config)#
interface vlan2
awplus(config-if)#
ip helper-address 192.168.1.100
Parameter
Description
<
ip-addr
>
Forwarding destination IP address for IP Helper.