Users Guide

To view the interfaces and ports on which you enabled UDP helper, use the show ip udp-helper command from EXEC
Privilege mode.
DellEMC#show ip udp-helper
--------------------------------------------------
Port UDP port list
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tf 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
DellEMC(conf-if-vl-100)#ip udp-broadcast-address 1.1.255.255
DellEMC(conf-if-vl-100)#show config
!
interface Vlan 100
ip address 1.1.0.1/24
ip udp-broadcast-address 1.1.255.255
untagged twentyFiveGigE 1/2
no shutdown
To view the configured broadcast address for an interface, use show interfaces command.
DellEMC#show interfaces vlan 100
Vlan 100 is up, line protocol is down
Address is 00:01:e8:0d:b9:7a, Current address is 00:01:e8:0d:b9:7a
Interface index is 1107787876
Internet address is 1.1.0.1/24
IP UDP-Broadcast address is 1.1.255.255
MTU 1554 bytes, IP MTU 1500 bytes
LineSpeed auto
ARP type: ARPA, ARP Timeout 04:00:00
Last clearing of "show interface" counters 00:07:44
Queueing strategy: fifo
Input Statistics:
0 packets, 0 bytes
Time since last interface status change: 00:07:44
Configurations Using UDP Helper
When you enable UDP helper and the destination IP address of an incoming packet is a broadcast address, Dell EMC Networking
OS 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
● UDP Helper with Subnet Broadcast Addresses
● UDP Helper with Configured Broadcast Addresses
● UDP Helper with No Configured Broadcast Addresses
UDP Helper with Broadcast-All Addresses
When the destination IP address of an incoming packet is the IP broadcast address, Dell EMC Networking OS rewrites the
address to match the configured broadcast address.
In the following illustration:
1. Packet 1 is dropped at ingress if you did not configure UDP helper address.
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IPv4 Routing