Usage 
Information
When a UDP broadcast packet is flooded out of an interface, and the outgoing interface is 
configured using this command, the outgoing packet’s IP destination address is replaced with 
the configured broadcast address.
Related 
Commands
debug ip udp-helper – enables debug and displays the debug information on a console.
show ip udp-helper – displays the configured UDP helper(s) on all interfaces.
ip udp-helper udp-port
Enable the UDP broadcast feature on an interface either for all UDP ports or a specified list of UDP ports.
E-Series, S4810
Syntax
ip udp-helper udp-port [udp-port-list]
To disable the UDP broadcast on a port, use the no ip udp-helper udp-port [udp-
port-list] command.
Parameters
udp-port-list
(OPTIONAL) Enter up to 16 comma-separated UDP port numbers.
NOTE: If you do not use this option, all UDP ports are considered 
by default.
Defaults none
Command Modes INTERFACE (config-if)
Command History
Version 8.3.7.0 Introduced on the S4810.
Pre-version 
8.3.7.0
Introduced on the E-Series ExaScale.
Usage 
Information
If you configure the ip helper-address command and ip udp-helper udp-port 
command, the behavior is that the UDP broadcast traffic with port numbers 67/68 is unicast 
relayed to the DHCP server per the ip helper-address configuration. This occurs 
regardless if the ip udp-helper udp-port command contains port numbers 67/68 or 
not.
If you only configure the ip udp-helper udp-port command, all the UDP broadcast 
traffic is flooded, including ports 67/68 traffic if those ports are part of the 
udp-port-list.
Related 
Commands
ip helper-address – configures the destination broadcast or host address for the DHCP server.
debug ip udp-helper – enables debug and displays the debug information on a console.
show ip udp-helper – displays the configured UDP helper(s) on all interfaces.
767