H3C S7500 Series Ethernet Switches Command Manual

Table Of Contents
Command Manual – UDP-Helper
H3C S7500 Series Ethernet Switches Chapter 1
UDP-Helper Configuration Commands
1-3
View
System view
Parameters
port: number of a UDP port to be configured as a UDP-Helper destination port, in the
range 1 to 65535 (except for 67 and 68).
dns: Specifies the DNS UDP port (port 53) as a UDP-Helper destination port.
netbios-ds: Specifies the NetBIOS-DS UDP port (port 138) as a UDP-Helper
destination port.
netbios-ns: Specifies the NetBIOS-NS UDP port (port 137) as a UDP-Helper
destination port.
tacacs: Specifies the TACACS UDP port (port 49) as a UDP-Helper destination port.
tftp: Specifies the TFTP UDP port (port 69) as a UDP-Helper destination port.
time: Specifies the time service UDP port (port 37) as a UDP-Helper destination port.
Description
Use the udp-helper port command to specify a UDP-Helper destination port.
Use the undo udp-helper port command to disable a port from being a UDP-Helper
destination port.
With UDP-Helper enabled, UDP broadcast packets with their destination port being the
six default UDP ports (that is, port 69, 53, 37, 137, 138, and 49) are forwarded to the
configured destination servers by default. After the UDP-Helper function is disabled, all
the configured UDP-Helper destination ports are cancelled, including the default UDP
ports.
Note that:
z Before configuring udp-helper port, you must enable UDP-Helper.
z When you view the configuration information by using the display
current-configuration command, information about default UDP ports is not
displayed. Such information is displayed only when a default port is disabled.
Examples
# Configure the DNS UDP port as a UDP-Helper destination port.
<H3C> system-view
System View: return to User View with Ctrl+Z.
[H3C] udp-helper port dns