The OpenThread UDP APIs may be invoked via the OpenThread CLI.

Form a network with at least two devices.

On node 1, open and bind the example UDP socket.

> udp open
> udp bind :: 1234

The :: specifies the IPv6 Unspecified Address.

On node 2, open the example UDP socket and send a simple message.

> udp open
> udp send fdde:ad00:beef:0:bb1:ebd6:ad10:f33 1234 hello

On node 1, you should see a print out similar to below:

5 bytes from fdde:ad00:beef:0:dac3:6792:e2e:90d8 49153 hello

• help
• bind
• close
• connect
• linksecurity
• open
• send

List the UDP CLI commands.

> udp help
help
bind
close
connect
open
send
Done

Assigns a name (i.e. IPv6 address and port) to the example socket.

• netif: the network interface to bind to.
  • not specified: Thread stack network interface.
  • -u: unspecified network interface.
  • -b: Backbone network interface.
  • -h: Host Thread network interface.
• ip: the unicast IPv6 address or the unspecified IPv6 address (::).
• port: the UDP port

Note: the netif parameter values (-u, -b, -h) are only valid if OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE is set.

> udp bind :: 1234
Done
> udp bind -u :: 1234
Done
> udp bind -b :: 1234
Done
> udp bind -h :: 1234
Done

Note: to receive datagrams sent to a multicast IPv6 address, the unspecified IPv6 address must be used. Using a multicast address for the <ip> argument is not supported. Also, the node must subscribe to the multicast group using ipmaddr add before it can receive UDP multicast.

Closes the example socket.

> udp close
Done

Specifies the peer with which the socket is to be associated.

• ip: the peer's IP address.
• port: the peer's UDP port.

> udp connect fdde:ad00:beef:0:bb1:ebd6:ad10:f33 1234
Done

The address can be an IPv4 address, which will be synthesized to an IPv6 address using the preferred NAT64 prefix from the network data.

Note: The command will return InvalidState when the preferred NAT64 prefix is unavailable.

> udp connect 172.17.0.1 1234
Connecting to synthesized IPv6 address: fdde:ad00:beef:2:0:0:ac11:1
Done

Indicates whether the link security is enabled or disabled.

> udp linksecurity
Enabled
Done

Enable link security.

> udp linksecurity enable
Done

Disable link security.

> udp linksecurity disable
Done

Opens the example socket.

> udp open
Done

Send a UDP message.

• ip: the destination address.
• port: the UDP destination port.
• message: the message to send.

> udp send fdde:ad00:beef:0:bb1:ebd6:ad10:f33 1234 hello
Done

The address can be an IPv4 address, which will be synthesized to an IPv6 address using the preferred NAT64 prefix from the network data.

Note: The command will return InvalidState when the preferred NAT64 prefix is unavailable.

> udp send 172.17.0.1 1234 hello
Sending to synthesized IPv6 address: fdde:ad00:beef:2:0:0:ac11:1
Done

Send a few bytes over UDP.

• ip: the IPv6 destination address.
• port: the UDP destination port.
• type: the type of the message:
  • -t: text payload in the value, same as without specifying the type.
  • -s: autogenerated payload with specified length indicated in the value.
  • -x: binary data in hexadecimal representation in the value.

> udp send fdde:ad00:beef:0:bb1:ebd6:ad10:f33 1234 -t hello
Done

> udp send fdde:ad00:beef:0:bb1:ebd6:ad10:f33 1234 -x 68656c6c6f
Done

> udp send fdde:ad00:beef:0:bb1:ebd6:ad10:f33 1234 -s 800
Done

Send a UDP message on a connected socket.

• message: the message to send.

> udp send hello
Done

Send a few bytes over UDP.

• type: the type of the message:
  • -t: text payload in the value, same as without specifying the type.
  • -s: autogenerated payload with specified length indicated in the value.
  • -x: binary data in hexadecimal representation in the value.

> udp send -t hello
Done

> udp send -x 68656c6c6f
Done

> udp send -s 800
Done