Show Ip Helper-Address - Cisco Small Business 300 1.1 Series Administration Manual

IP Addressing Commands
78-20269-01 Command Line Interface Reference Guide
system mode router command.
The ip helper-address command forwards specific UDP broadcast packets from
one interface to another.
Many helper addresses may be defined. However, the total number of
address-port pairs is limited to 128 for the device.
The setting of a helper address for a specific interface has precedence over the
setting of a helper address for all the interfaces.
Forwarding of BOOTP/DHCP (ports 67, 68) cannot be enabled with this command.
Use the DHCP relay commands to relay BOOTP/DHCP packets.
The ip helper-address command specifies a UDP port number to which UDP
broadcast packets with that destination port number are forwarded. By default, if
no UDP port number is specified, the device forwards UDP broadcast packets for
the following six services:
•
IEN-116 Name Service (port 42)
•
DNS (port 53)
•
NetBIOS Name Server (port 137)
•
NetBIOS Datagram Server (port 138)
•
TACACS Server (port 49)
•
Time Service (port 37)
Example
The following example enables the forwarding of User Datagram Protocol (UDP)
broadcasts received on all interfaces to specific UDP ports of a destination IP
address.
Console (config)#
ip helper-address all

35.15 show ip helper-address

Use the show ip helper-address Privileged EXEC mode command to display the IP
helper addresses configuration on the system.
Syntax
show ip helper-address
172.16.9.9 49 53
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