219 
Step Command  Remarks 
time
 } 
4.  Enter interface view. 
interface
 interface-type interface-number N/A 
5.  Specify a destination 
server for UDP helper to 
convert broadcast to 
unicast. 
udp-helper
 
server
 ip-address [ 
global
 | 
vpn-instance
 vpn-instance-name ] 
By default, no destination 
server is specified. 
If you specify multiple 
destination servers, UDP 
helper creates one copy for 
each server. 
Use this command on the 
interface that receives 
broadcast packets. 
 
Configuring UDP helper to convert broadcast to 
multicast 
You can configure UDP helper to convert broadcast packets with specific UDP port numbers to 
multicast packets. 
Upon receiving a UDP broadcast packet, UDP helper uses the configured UDP ports to match the 
UDP destination port number of the packet. 
•  If a match is found, UDP helper duplicates the packet and modifies the destination IP address of 
the copy to the configured multicast address. Then UDP helper forwards the packet to the 
multicast group. 
•  If no match is found, UDP helper does not process the packet. 
To configure UDP helper to convert broadcast to multicast: 
 
Step Command  Remarks 
1.  Enter system view. 
system-view 
N/A 
2.  Enable UDP helper. 
udp-helper enable 
By default, UDP helper is 
disabled. 
3.  Specify a UDP port 
number. 
udp-helper port
 { port-number | 
dns
 | 
netbios
-
ds
 | 
netbios-ns 
| 
tacacs
 | 
tftp
 | 
time
 } 
By default, no UDP port 
numbers are specified. 
4.  Enter interface view. 
interface
 interface-type interface-number N/A 
5.  Specify a destination 
multicast address for 
UDP helper to convert 
broadcast to multicast. 
udp-helper broadcast-map
 
multicast-address [ 
acl
 acl-number ] 
By default, no destination 
multicast address is specified 
for UDP helper. 
If you specify multiple multicast 
addresses, UDP helper 
creates one copy for each 
address. 
Use this command on the 
interface that receives 
broadcast packets.