Node.js socket.setMulticastLoopback() Method

The socket.setMulticastLoopback() method is an inbuilt application programming interface of class Socket within dgram module which is used to set or clear the IP_MULTICAST_LOOP socket option which helps the server in receiving the multicast packet at the local interface.

Syntax:

const socket.setMulticastLoopback( flag )

Parameters: This method takes the Boolean value as a parameter true for enabling the IP_MULTICAST_LOOP socket option and false for disabling it.

Return Value: This method does not return any value.

Example 1: In this example, we will see the use of the socket.setMulticastLoopback() method

Filename: index.js

Output: 

UDP String: Hello

Example 2: In this example, we will see the use of the socket.setMulticastLoopback() method

Filename: index.js

Output:

server listening 0.0.0.0:1234
UDP String: Hello

Run the index.js file using the following command:

node index.js

Reference: https://nodejs.org/dist/latest-v12.x/docs/api/dgram.html#dgram_socket_setmulticastloopback_flag