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

 

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

Any view

Parameters

vlan-id: ID of a VLAN.

Description

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

Vlan-interface1      192.1.1.2           0

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.

Examples

# 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.

[H3C] udp-helper port dns

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