Users Guide

UDP Helper
User datagram protocol (UDP) helper allows you to direct the forwarding IP/UDP broadcast traffic by creating special broadcast
addresses and rewriting the destination IP address of packets to match those addresses.
Configure UDP Helper
To configure Dell Networking OS to direct UDP broadcast, enable UDP helper and specify the UDP ports for which traffic is
forwarded. See 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 and Using the UDP Helper show Command
Dell(conf-if-gi-1/1)#ip udp-helper udp-port 1000
Dell(conf-if-gi-1/1)#show config
!
interface GigabitEthernet 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
--------------------------------------------------
Gi 1/1 1000
Configuring a Broadcast Address
To configure a broadcast address, use the following command.
• Configure a broadcast address on an interface.
ip udp-broadcast-address
Examples of Configuring and Viewing a Broadcast Address
Dell(conf-if-vl-100)#ip udp-broadcast-address 1.1.255.255
Dell(conf-if-vl-100)#show config
IPv4 Routing 358