Administrator Guide
1 Enable UDP helper and specify the UDP ports for which traffic is forwarded. Refer to
Enabling UDP Helper.
Important Points to Remember
• The existing ip directed broadcast command is rendered meaningless if you enable UDP helper
on the same interface.
• The broadcast traffic rate should not exceed 200 packets per second when you enable UDP helper.
• You may specify a maximum of 16 UDP ports.
• UDP helper is compatible with IP helper (ip helper-address):
• UDP broadcast traffic with port number 67 or 68 are unicast to the dynamic host configuration
protocol (DHCP) server per the ip helper-address configuration whether or not the UDP port
list contains those ports.
• If the UDP port list contains ports 67 or 68, UDP broadcast traffic is forwarded on those ports.
Enabling UDP Helper
To enable UDP helper, use the following command.
• Enable UPD helper.
ip udp-helper udp-ports
Example of Enabling UDP Helper
Example of the show ip udp-helper Command
Dell(conf-if-te-1/1)#ip udp-helper udp-port 1000
Dell(conf-if-te-1/1)#show config
!
interface TenGigabitEthernet 1/1
ip address 2.1.1.1/24
ip udp-helper udp-port 1000
no shutdown
To view the interfaces and ports on which you enabled UDP helper, use the show ip udp-helper
command from EXEC Privilege mode.
Dell#show ip udp-helper
---------------------------
Port UDP port list
--------------------------
TenGig 1/1 1000
Configurations Using UDP Helper
When you enable UDP helper and the destination IP address of an incoming packet is a broadcast address,
the system suppresses the destination address of the packet.
The following sections describe various configurations that employ UDP helper to direct broadcasts.
• UDP Helper with Broadcast-All Addresses
IPv4 Routing 462