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 server 1-3

1.1.3 reset udp-helper packet 1-4

1.1.4 udp-helper enable. 1-5

1.1.5 udp-helper port 1-5

1.1.6 udp-helper server 1-6

 

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

Default Level

2: System view

Parameter

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.

Table 1-1 Description on major fields of the debugging udp-helper event command

Field	Description
TTL Exceed!	The TTL timer expires.
Dest Ip(Num) is not routable or the packet is from the device itself.	The packet will not be processed because no outbound interface is found or the packet is sent out of the local device itself.
Pointer of the route table outer interface is NULL!	The pointer of the outbound interface of the found routing entry is null.
Making MBUF continuous failed	Fails to arrange MBUF space.
Fail to input the message to the queue, maybe it's already full. The return code is : number	Writing the message failed, possibly because the queue is full. The error code number is returned.
Receive invalid DHCP packet	An invalid DHCP packet is received.
Receive a dhcp REQUEST packet	A DHCP request packet is received.
Receive a dhcp RESPONSE packet	A DHCP response packet is received.
UNIT number is not in Fabric Discard the dhcp RESPONSE packet	The unit with the Unit ID number is not in the Fabric, and the DHCP response packet is discarded.
Cannot find the saved xid of the dhcp RESPONSE packet Discard the dhcp RESPONSE packet	The saved xid value cannot be found, and the DHCP response packet is discarded.
Convert xid to saved xid	Convert xid and save it.
Send the packet to udp module in DHCP case.	Send DHCP UDP packets to the UDP module.
Self UNIT is MASTER UNIT Send dhcp RESPONSE packet to udp module	The local unit is the Master Unit, which sends DHCP response packets to the UDP module.
Self UNIT is SLAVE UNIT Send dhcp RESPONSE packet to MASTER UNIT : number	The local unit is the Slave Unit, which sends DHCP response packets to the Master Unit with the ID number for processing.

 

Table 1-2 Description on major fields of the debugging udp-helper packet command

Field	Description
Dest Ip	Destination IP address
Source Ip	Source IP address.
Dest Port	Destination port number.
New Dest Ip	New destination IP address of the packet after being forwarded through UDP Helper.
Intercept a UDP packet.	A UDP packet is intercepted.
Copy the packet and send it to the UDP module.	Copy a packet and send the original packet to the UDP module.
New Dest Ip ip-address Forward the packet to destination server	Forward a packet to the destination server with the new destination IP address ip-address.
Send the packet to udp module without relay.	Send a packet to the UDP module directly without relaying.

 

Example

# Configure port 520 to forward packets to the server at 2.2.2.2 and enable packet debugging for UDP Helper.

<Sysname> system-view

[Sysname] udp-helper enable

[Sysname] udp-helper port 520

[Sysname] interface Vlan-interface 20

[Sysname-Vlan-interface20] udp-helper server 2.2.2.2

[Sysname-Vlan-interface20] return

<Sysname> debugging udp-helper packet

*Aug 11 08:20:46:00 2005 Sysname UDPH/7/UDPHelper_Pkt:

Dest Ip(1.1.1.255)    Source Ip(1.1.1.5)    Dest Port(520)

 Prompt: Intercept a UDP packet.

// A UDP packet is received, in which the source IP address is 1.1.1.5, the destination IP address is 1.1.1.255, and the destination port number is 520.

*Aug 11 08:20:46:01 2005 Sysname UDPH/7/UDPHelper_Pkt:

Dest Ip(1.1.1.255)    Source Ip(1.1.1.5)    Dest Port(520)

 Prompt: Copy the packet and send it to the UDP module.

// Copy the packet and send it to the UDP module. In the original packet, the source IP address is 1.1.1.5, the destination IP address is 1.1.1.255, and the destination port number is 520.

*Aug 11 08:20:46:02 2005 Sysname UDPH/7/UDPHelper_Pkt:

Dest Ip(1.1.1.255)    Source Ip(1.1.1.5)    Dest Port(520)

New Dest Ip(2.2.2.2)

 Prompt: Forward the packet to destination server

// Forward the packet to the destination server at 2.2.2.2. In the packet, the source IP address is 1.1.1.5, the destination IP address is 1.1.1.255, and the destination port number is 520.

1.1.2  display udp-helper server

Syntax

display udp-helper server [ interface interface-type interface-number ]

View

Any view

Default Level

2: System view

Parameter

interface interface-type interface-number: Specifies an interface by interface type and interface number.

Description

Use the display udp-helper server command to display the information of forwarded UDP packets on the specified interface or all interfaces.

If interface-type interface-number is not specified, this command displays the information of forwarded UDP packets on all interfaces.

Example

# Display the information of forwarded UDP packets on the interface VLAN-interface 1.

<Sysname> 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 the interface VLAN-interface 1 is 192.1.1.2, and that no packets are forwarded to the destination server.

1.1.3  reset udp-helper packet

Syntax

reset udp-helper packet

View

User view

Default Level

2: System view

Parameter

None

Description

Use the reset udp-helper packet command to clear the statistics of UDP packets forwarded.

Related command: display udp-helper serve.

Example

# Clear the statistics of the forwarded UDP packets.

<Sysname> reset udp-helper packet

1.1.4  udp-helper enable

Syntax

udp-helper enable

undo udp-helper enable

View

System view

Default Level

2: System view

Parameter

None

Description

Use the udp-helper enable command to enable UDP Helper. The device enabled with UDP Helper functions as a relay agent that converts UDP broadcast packets into unicast packets and forwards them to a specified destination server.

Use the undo udp-helper enable command to disable UDP Helper.

By default, UDP Helper is disabled.

Example

# Enable UDP Helper

<Sysname> system-view

[Sysname] udp-helper enable

1.1.5  udp-helper port

Syntax

udp-helper port { port-number | dns | netbios-ds | netbios-ns | tacacs | tftp | time }

undo udp-helper port { port-number | dns | netbios-ds | netbios-ns | tacacs | tftp | time }

View

System view

Default Level

2: System view

Parameter

port-number: UDP port number with which packets need to be forwarded, in the range of 1 to 65535 (except 67 and 68).

dns: Forwards DNS data packets. The corresponding UDP port number is 53.

netbios-ds: Forwards NetBIOS data packets. The corresponding UDP port number is 138.

netbios-ns: Forwards NetBIOS name service data packets. The corresponding UDP port number is 137.

tacacs: Forwards terminal access controller access control system (TACACS) data packet. The corresponding UDP port number is 49.

tftp: Forwards TFTP data packets. The corresponding UDP port number is 69.

time: Forwards time service data packets. The corresponding UDP port number is 37.

Description

Use the udp-helper port command to enable the forwarding of packets with the specified UDP port number.

Use the undo udp-helper port command to remove the configured UDP port numbers.

By default, the UDP Helper enabled device forwards broadcast packets with any of the six UDP destination port numbers 69, 53, 37, 137, 138 and 49. The configured UDP port numbers (including the default UDP port numbers) will all be removed if UDP Helper is disabled.

Example

# Forward broadcast packets with the UDP destination port number 100.

<Sysname> system-view

[Sysname] udp-helper port 100

1.1.6  udp-helper server

Syntax

udp-helper server ip-address

undo udp-helper server [ ip-address ]

View

VLAN interface view

Default Level

2: System view

Parameter

ip-address: IP address of the destination server, in dotted decimal notation.

Description

Use the udp-helper server command to specify the destination server which UDP packets need to be forwarded to.

Use the undo udp-helper server command to remove the destination server.

No destination server is configured by default.

By default, you can configure up to 20 destination servers on an interface.

Note that you will remove all the destination servers on an interface if you carry out the undo udp-helper server command without the ip-address argument.

Related command: display udp-helper server.

Example

# Specify the IP address of the destination server as 192.1.1.2 on the interface VLAN-interface 100.

<Sysname> system-view

[Sysname] interface vlan-interface 100

[Sysname-Vlan-interface100] udp-helper server 192.1.1.2