Specifications
Table Of Contents
- Title Page
- Notice
- Contents
- acl Commands
- acl-edit Commands
- aging Commands
- arp Commands
- cli Commands
- configure Command
- copy Command
- dvmrp Commands
- enable Command
- erase Command
- exit Command
- file Commands
- filters Commands
- http Commands
- igmp Commands
- interface Commands
- ip Commands
- ip-router Commands
- Command Summary
- ip-router authentication add key-chain
- ip-router authentication create key-chain
- ip-router global add
- ip-router global set
- ip-router global set trace-options
- ip-router global set trace-state
- ip-router global use provided_config
- ip-router kernel trace
- ip-router policy add filter
- ip-router policy add optional-attributes-list
- ip-router policy aggr-gen destination
- ip-router policy create aggregate-export-source
- ip-router policy create aggr-gen-dest
- ip-router policy create aggr-gen-source
- ip-router policy create aspath-export-source
- ip-router policy create bgp-export-destination
- ip-router policy create bgp-export-source
- ip-router policy create bgp-import-source
- ip-router policy create direct-export-source
- ip-router policy create filter
- ip-router policy create optional-attributes-list
- ip-router policy create ospf-export-destination
- ip-router policy create ospf-export-source
- ip-router policy create ospf-import-source
- ip-router policy create rip-export-destination
- ip-router policy create rip-export-source
- ip-router policy create rip-import-source
- ip-router policy create static-export-source
- ip-router policy create tag-export-source
- ip-router policy export destination
- ip-router policy import source
- ip-router policy redistribute
- ip-router show configuration file
- ip-router show state
- ipx Commands
- l2-tables Commands
- logout Command
- multicast Commands
- mtrace Command
- negate Command
- no Command
- ospf Commands
- Command Summary
- ospf add interface
- ospf add nbma-neighbor
- ospf add network
- ospf add stub-host
- ospf add virtual-link
- ospf create area
- ospf create-monitor
- ospf monitor
- ospf set area
- ospf set ase-defaults
- ospf set export-interval
- ospf set export-limit
- ospf set interface
- ospf set monitor-auth-method
- ospf set trace-options
- ospf set virtual-link
- ospf show
- ospf start|stop
- ping Command
- port Commands
- qos Commands
- reboot Command
- rip Commands
- save Command
- show Command
- snmp Commands
- statistics Commands
- stp Commands
- system Commands
- Command Summary
- system image add
- system image choose
- system image delete
- system image list
- system promimage upgrade
- system set bootprom
- system set contact
- system set date
- system set dns
- system set location
- system set name
- system set password
- system set poweron-selftest
- system set syslog
- system set terminal
- system show
- traceroute Command
- vlan Commands
Chapter 17: ip Commands
17 - 4 SSR Command Line Interface Reference Manual
ip helper-address
Purpose
Configure the router to forward specific UDP broadcast packets across interfaces.
Format
ip helper-address interface
<interface-name> <helper-address>
<udp-port#>
Mode
Configure
Description
The
ip
helper-address
command allows the user to forward specific UDP
broadcast from one interface to another. Typically, broadcast packets from one
interface are not forwarded (routed) to another interface. However, some applications
use UDP broadcast to detect the availability of a service. Other services, for example
BOOTP/DHCP require broadcast packets to be routed so that they can provide services
to clients on another subnet. An IP helper can be configured on each interface to have
UDP broadcast packets forwarded to a specific host for a specific service.
The ip helper-address command allows the user to specify a UDP port number for
which UDP broadcast packets with that destination port number will be forwarded. By
default, if no UDP port number is specified, the SSR will forward UDP broadcast
packets for the following six services:
• BOOTP/DHCP (port 67 and 68)
• DNS (port 37)
• NetBIOS Name Server (port 137)
• NetBIOS Datagram Server (port 138)
• TACACS Server (port 49)
• Time Service (port 37)
Parameters
<interface-name>
Name of the IP interface where UDP broadcast is to be for-
warded to the helper address.
<helper-address>
Address of the host where UDP broadcast packets should
be forwarded.