Udp Helper; Configure Udp Helper; Important Points To Remember; Enabling Udp Helper - Dell S6100 Configuration Manual

ip unreachable
To view if ICMP unreachable messages are sent on the interface, use the show config command in INTERFACE mode. If it is not listed
in the show config command output, it is enabled. Only non-default information is displayed in the show config command output.

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
To view the interfaces and ports on which you enabled UDP helper, use the show ip udp-helper command from EXEC Privilege
mode.

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
!
interface Vlan 100
ip address 1.1.0.1/24
ip udp-broadcast-address 1.1.255.255
untagged TenGigabitEthernet 1/1/2/1
no shutdown
IPv4 Routing 425