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

mdc-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