Contents

UDP helper commands· 1

display udp-helper interface· 1

reset udp-helper statistics· 1

udp-helper broadcast-map· 2

udp-helper enable· 3

udp-helper port 3

udp-helper server 4

 

UDP helper commands

display udp-helper interface

Use display udp-helper interface to display information about broadcast to unicast conversion by UDP helper on an interface.

Syntax

display udp-helper interface interface-type interface-number

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

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

Usage guidelines

This command displays information about destination servers and total number of unicast packets converted from UDP broadcast packets by UDP helper.

Examples

# Display information about broadcast to unicast conversion by UDP helper on VLAN-interface 100.

<Sysname> display udp-helper interface vlan-interface 100

Interface                Server VPN instance           Server address Packets sent

Vlan-interface100        N/A                           192.1.1.2      0

Table 1 Command output

Field	Description
Interface	Interface name.
Server VPN instance	VPN instance to which the destination server belongs.
Server address	Destination server to which UDP packets are forwarded.
Packets sent	Number of unicast packets that are converted from broadcast packets by UDP helper.

 

Related commands

reset udp-helper statistics

udp-helper server

reset udp-helper statistics

Use reset udp-helper statistics to clear statistics about broadcast to unicast conversion by UDP helper.

Syntax

reset udp-helper statistics

Views

User view

Predefined user roles

network-admin

Examples

# Clear the statistics about broadcast to unicast conversion by UDP helper.

<Sysname> reset udp-helper statistics

Related commands

display udp-helper interface

udp-helper broadcast-map

Use udp-helper broadcast-map to specify a multicast address for UDP helper to convert broadcast to multicast.

Use undo udp-helper broadcast-map to restore the default.

Syntax

udp-helper broadcast-map multicast-address [ acl acl-number ]

undo udp-helper broadcast-map multicast-address

Default

No multicast address is specified for UDP helper to convert broadcast to multicast.

Views

Interface view

Predefined user roles

network-admin

Parameters

multicast-address: Specifies the destination multicast address to which the destination broadcast address is converted.

acl acl-number: Specifies an ACL by its number. The ACL filters incoming broadcast packets for UDP helper. Packets permitted by the ACL can be converted. If no ACL is specified, all incoming broadcast packets are checked for UDP helper.

·     For a basic ACL, the value range is 2000 to 2999.

·     For an advanced ACL, the value range is 3000 to 3999.

Usage guidelines

Use this command on the interface that receives broadcast packets.

You can configure a maximum of 20 unicast and multicast addresses for UDP helper to convert broadcast packets.

When you specify an ACL, follow these restrictions and guidelines:

·     If the ACL does not exist or does not contain a rule, UDP helper does not convert broadcast to multicast.

·     If you specify the vpn-instance keyword for an ACL rule, the rule takes effect only on VPN packets. If you do not specify the vpn-instance keyword for an ACL rule, the rule takes effect only on public network packets.

Examples

# Configure UDP helper to convert received broadcast packets on VLAN-interface 100 to multicast packets destined for 225.0.0.1.

<Sysname> system-view

[Sysname] interface vlan-interface 100

[Sysname-Vlan-interface100] udp-helper broadcast-map 225.0.0.1

udp-helper enable

Use udp-helper enable to enable UDP helper.

Use undo udp-helper enable to disable UDP helper.

Syntax

udp-helper enable

undo udp-helper enable

Default

UDP helper is disabled.

Views

System view

Predefined user roles

network-admin

Usage guidelines

For UDP helper to take effect on an interface, make sure the following conditions are met:

·     UDP helper is enabled.

·     A UDP port number is specified by using the udp-helper port command.

·     Packet conversion for UDP helper is configured on the interface.

Examples

# Enable UDP helper.

<Sysname> system-view

[Sysname] udp-helper enable

Related commands

udp-helper port

udp-helper server

udp-helper broadcast-map

udp-helper port

Use udp-helper port to specify a UDP port number for UDP helper.

Use undo udp-helper port to remove UDP port numbers.

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 }

Default

No UDP port numbers are specified for UDP helper.

Views

System view

Predefined user roles

network-admin

Parameters

port-number: Specifies a UDP port number in the range of 1 to 65535 (except 67 and 68).

dns: Specifies the UDP port 53 used by DNS packets.

netbios-ds: Specifies the UDP port 138 used by NetBIOS distribution service packets.

netbios-ns: Specifies the UDP port 137 used by NetBIOS name service packets.

tacacs: Specifies the UDP port 49 used by TACACS packets.

tftp: Specifies the UDP port 69 used by TFTP packets.

time: Specifies the UDP port 37 used by time protocol packets.

Usage guidelines

Upon receiving a UDP broadcast or multicast packet, UDP helper uses the specified UDP ports to match the UDP destination port number of the packet.

To specify a UDP port, you can specify the port number or the protocol keyword. For example, udp-helper port 53 and udp-helper port dns specify the same UDP port.

You can specify a maximum of 256 UDP ports on a device.

Examples

# Specify the UDP port 100 for UDP helper.

<Sysname> system-view

[Sysname] udp-helper port 100

udp-helper server

Use udp-helper server to specify a destination server for UDP helper to convert broadcast to unicast.

Use undo udp-helper server to remove a destination server.

Syntax

udp-helper server ip-address [ global | vpn-instance vpn-instance-name ]

undo udp-helper server [ ip-address [ global | vpn-instance vpn-instance-name ] ]

Default

No destination server is specified for UDP helper to convert broadcast to unicast.

Views

Interface view

Predefined user roles

network-admin

Parameters

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

global: Forwards converted unicast packets to the server on the public network.

vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance to which the server belongs. The vpn-instance-name argument represents the VPN instance name, a case-sensitive string of 1 to 31 characters.

Usage guidelines

Specify destination servers on an interface that receives UDP broadcast packets. If the packets' destination UDP port numbers match the UDP helper ports, UDP helper forwards the broadcasts to the specified servers.

You can specify a maximum of 20 unicast and multicast addresses for UDP helper to convert broadcast packets on an interface.

If you do not specify the ip-address argument, the undo udp-helper server command removes all destination servers on the interface.

A destination server with the global keyword and the same destination server with the vpn-instance vpn-instance-name option do not overwrite each other. If you specify only the IP address, UDP helper forwards converted unicast packets in the VPN to which the receiving interface belongs. If the interface is not bound to any VPN instance, UDP helper forwards the unicast packets on the public network.

Examples

# Specify the destination server 192.1.1.2 for UDP helper to convert broadcast to unicast on VLAN-interface 100.

<Sysname> system-view

[Sysname] interface vlan-interface 100

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

# Specify the destination server 192.1.1.2 on the public network for UDP helper to convert broadcast to unicast on VLAN-interface 100.

<Sysname> system-view

[Sysname] interface vlan-interface 100

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

Related commands

display udp-helper interface