H3C Technologies H3C WX3000 Series Unified Switches - Manual (Page 671)

68-2
Protocol UDP port number
TFTP (Trivial File Transfer Protocol) 69
Time Service 37
Configuring UDP Helper
Follow these steps to configure UDP Helper:
To do… Use the command… Remarks
Enter system view system-view —
Enable UDP Helper udp-helper enable
Required
Disabled by default.
Specify a UDP port number
udp-helper port { port-number |
dns | netbios-ds | netbios-ns |
tacacs | tftp | time }
Optional
By default, the device enabled with
UDP Helper forwards the
broadcast packets containing any
of the six port numbers 53, 138,
137, 49, 69 and 37.
Enter VLAN interface view interface Vlan-interface vlan-id —
Specify the destination server to
which the UDP packets are to be
forwarded
udp-helper server ip-address
Required
No destination server is specified
by default.
z
You need to enable UDP Helper before specifying any UDP port to match UDP broadcasts;
otherwise, the configuration fails. When the UDP helper function is disabled, all configured UDP
ports are disabled, including the default ports.
z
The dns, netbios-ds, netbios-ns, tacacs, tftp, and time keywords correspond to the six default
ports. You can configure the default ports by specifying port numbers or the corresponding
parameters. For example, udp-helper port 53 and udp-helper port dns specify the same port.
z
You can specify up to 20 destination server addresses on a VLAN interface.
z
If UDP Helper is enabled after a destination server is configured for a VLAN interface, the
broadcasts from interfaces belonging to the VLAN and having a matching UDP port will be unicast
to the destination server.
Displaying and Maintaining UDP Helper
To do… Use the command… Remarks
Display the UDP broadcast relay
forwarding information of a specified
VLAN interface on the device
display udp-helper server [ interface
vlan-interface vlan-id ]
Available in any view