H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – UDP-Helper
H3C S7500 Series Ethernet Switches Chapter 1
UDP-Helper Configuration
1-3
Caution:
z You need to enable the UDP-Helper function before specifying a UDP-Helper
destination port.
z The dns, netbios-ds, netbios-ns, tacacs, tftp, and time keywords refers to the six
default UDP ports. You can configure a default port to be a UDP-Helper destination
port by specifying the corresponding port number or the corresponding keyword.
For example, udp-helper port 53 and udp-helper port dns specify the same port
as a UDP-Helper destination port.
z The display current-configuration command does not display the default UDP
ports that are configured to be UDP-Helper destination ports.
z After UDP-Helper is disabled, all the configured UDP ports are cancelled, including
the default ports.
z You can configure up to 40 UDP ports as UDP-Helper destination ports on a device.
z You can configure up to 20 destination servers on a VLAN interface.
z If the destination server is configured on a VLAN interface, the UDP broadcast
packets received from the ports in the VLAN with specific UDP-Helper destination
ports are forwarded to the destination server configured on the VLAN interface.
1.3 Displaying and Maintaining UDP-Helper Configuration
To do… Use the command… Remarks
Display the information about the
destination servers and the
number of the packets forwarded
to each destination server
display udp-helper server
[ interface vlan-interface
vlan-id ]
Available in any
view
Clear the statistics about
packets forwarded by
UDP-Helper
reset udp-helper packet
Available in user
view
1.4 UDP-Helper Configuration Example
1.4.1 Network requirements
The IP address of VLAN 1 interface is 10.110.1.1/16. The VLAN interface is connected
to the network segment 10.110.0.0/16. Configure to forward the broadcast UDP
packets whose destination UDP port number is 55 to the server with its IP address
being 202.38.1.2/24.