Command Manual – UDP Helper
H3C S9500 Series Routing Switches Table of Contents
Table of Contents
Chapter 1 UDP Helper Configuration Commands...................................................................... 1-1
1.1 UDP Helper Configuration Commands.............................................................................. 1-1
1.1.1 debugging udp-helper ............................................................................................. 1-1
1.1.2 display udp-helper ................................................................................................... 1-1
1.1.3 udp-helper enable ................................................................................................... 1-2
1.1.4 udp-helper port ........................................................................................................ 1-3
1.1.5 udp-helper server .................................................................................................... 1-4
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Command Manual – UDP Helper
H3C S9500 Series Routing Switches Chapter 1 UDP Helper Configuration Commands
Chapter 1 UDP Helper Configuration Commands
1.1 UDP Helper Configuration Commands
1.1.1 debugging udp-helper
Syntax debugging udp-helper { event | packet [ receive | send ] } undo debugging udp-helper { event | packet [ receive | send ] }
View
User view
Parameters event : Enables event debugging for UDP Helper. packet : Enables packet debugging for UDP Helper. receive : Enables incoming packet debugging for UDP Helper. send : Enables outgoing packet debugging for UDP Helper.
Description
Use the debugging udp-helper command to enable UDP Helper debugging.
Use the undo debugging udp-helper command to disable UDP Helper debugging.
By default, UDP Helper debugging is disabled.
Examples
# Enable packet debugging for UDP Helper.
<H3C> debugging udp-helper packet
1.1.2 display udp-helper
Syntax display udp-helper { server [ interface vlan-interface vlan-id ] | port }
View
Parameters
Any view vlan-id : ID of a VLAN.
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Command Manual – UDP Helper
H3C S9500 Series Routing Switches
Description
Chapter 1 UDP Helper Configuration Commands
Use the display udp-helper server command to display the information of the destination server corresponding to the VLAN interface.
Use the display udp-helper port command to display the configuration of the global
UDP ports.
Examples
# Display the information of the destination server corresponding to VLAN-interface 1.
<H3C> display udp-helper server interface vlan-interface 1 interface name server address packets sent
The information above shows that the IP address of the destination server corresponding to VLAN-interface 1 is 192.1.1.2, and no packets have been forwarded.
# Display the configuration of the global UDP ports.
<H3C> display udp-helper port
Now, the following config udp-helper port exist(s):
37(time), 49(tacacs), 53(dns), 34, 89, 456, 10000-10005
The information above shows the configuration of the global UDP ports (including the default port 37, 49, 53 and the configured ports) when UDP helper is enabled.
1.1.3 udp-helper enable
Syntax udp-helper enable udp-helper enable
View
System view
Parameters
None
Description
Use the udp-helper enable command to enable the function of forwarding UDP broadcast packets.
Use the undo udp-helper enable command to disable the function.
By default, the function of forwarding UDP broadcast packets is disabled.
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Command Manual – UDP Helper
H3C S9500 Series Routing Switches
Examples
Chapter 1 UDP Helper Configuration Commands
# Enable the function of forwarding UDP broadcast packets.
<H3C>system-view
System View: return to User View with Ctrl+Z.
[H3C] udp-helper enable
1.1.4 udp-helper port
Syntax udp-helper port { port | dns | netbios-ds | netbios-ns | tacacs | tftp | time } undo udp-helper port { port | dns | netbios-ds | netbios-ns | tacacs | tftp | time }
View
System view
Parameters port : UDP port number, in the range of 1 to 65535. Packets with this UDP port number can be forwarded. Up to 250 ports are supported besides the default ports. The UDP
Helper enabled device cannot forward DHCP broadcast packets, and therefore, the
UDP port number cannot be set to 67 or 68.. dns : Refers to domain name system (DNS), whose UDP port number is 53. netbios-ds : Refers to NetBIOS datagram service (netbios-ds), whose UDP port number is 138. netbios-ns : Refers to NetBIOS name service (netbios-ns), whose UDP port number is
137. tacacs : Refers to terminal access controller access control system (TACACS), whose
UDP port number is 49. tftp : Refers to trivial transfer protocol (TFTP), whose UDP port number is 69. time : Refers to time service, whose UDP port number is 37.
Description
Use the udp-helper port command to specify the port number that UDP packets to be forwarded contain.
Use the undo udp-helper port command to remove the configuration.
Examples
# Specify the port corresponding to the DNS protocol as an UDP port.
<H3C>system-view
System View: return to User View with Ctrl+Z.
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Command Manual – UDP Helper
H3C S9500 Series Routing Switches
[H3C] udp-helper port dns
Chapter 1 UDP Helper Configuration Commands
1.1.5 udp-helper server
Syntax udp-helper server ip-address undo udp-helper server [ ip-address ]
View
VLAN interface view
Parameters ip-address : IP address of the destination server, in dotted decimal notation. This argument can be the address of a host or the broadcast address of a subnet. Up to 20 destination servers can be configured on a VLAN virtual interface.
Description
Use the udp-helper server command to specify the destination server to which the
UDP packets are to be forwarded.
Use the undo udp-helper server command to remove the configured destination server.
No destination server is configured by default.
Related commands: display udp-helper .
Examples
# Specify to forward UDP packets to the destination server at IP address 192.1.1.2.
<H3C>system-view
System View: return to User View with Ctrl+Z.
[H3C]interface Vlan-interface 1
[H3C-Vlan-interface1] udp-helper server 192.1.1.2
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