Command Reference Guide

IP Helper Commands
CLI Command Reference
September 2014 Page 548
HP Moonshot Switch Module CLI Command Reference
ip helper-address (Global Config)
Use this command to configure the relay of certain UDP broadcast packets received on any interface. This
command can be invoked multiple times, either to specify multiple server addresses for a given UDP port
number or to specify multiple UDP port numbers handled by a specific server.
Example: To relay DHCP packets received on any interface to two DHCP servers, 10.1.1.1 and 10.1.2.1, use
the following commands:
(Routing)#config
(Routing)(config)#ip helper-address 10.1.1.1 dhcp
(Routing)(config)#ip helper-address 10.1.2.1 dhcp
Example: To relay UDP packets received on any interface for all default ports to the server at 20.1.1.1, use
the following commands:
(Routing)#config
(Routing)(config)#ip helper-address 20.1.1.1
Default No helper addresses are configured.
Format
ip helper-address server-address [dest-udp-port | dhcp | domain | isakmp | mobile-ip
| nameserver | netbios-dgm | netbios-ns | ntp | pim-auto-rp | rip | tacacs | tftp |
time]
Mode Global Config
Parameter Description
server-address The IPv4 unicast or directed broadcast address to which relayed UDP broadcast packets are
sent. The server address cannot be an IP address configured on any interface of the local
router.
dest-udp-port A destination UDP port number from 0 to 65535.
port-name The destination UDP port may be optionally specified by its name. Whether a port is
specified by its number or its name has no effect on behavior. The names recognized are as
follows:
• dhcp (port 67)
• domain (port 53)
• isakmp (port 500)
• mobile-ip (port 434)
•nameserver (port 42)
• netbios-dgm (port 138)
• netbios-ns (port 137)
• ntp (port 123)
• pim-auto-rp (port 496)
•rip (port 520)
• tacacs (port 49)
•tftp (port 69)
•time (port 37)
Other ports must be specified by number.