Golang : How to detect a server/machine network interface capabilities?

Problem :

You want to know which network interfaces on a server that support Broadcast, Loopback, PointToPoint or Multicast networking capabilities. How to do that in Golang?

Solution :

Use the net.Interfaces() function to retrieve all the available network interfaces on the server, then check each interfaces' Flags.

For example :

 package main

 import (
 "fmt"
 "net"
 "strings"
 )

 func main() {

 interfaces, err := net.Interfaces()

 if err != nil {
 fmt.Print(err)
 return
 }

 for _, i := range interfaces {

 fmt.Printf("Name : %v \n", i.Name)

 // see http://golang.org/pkg/net/#Flags
 fmt.Println("Interface type and supports : ", i.Flags.String())

 if strings.Contains(i.Flags.String(), "up") {
 fmt.Println("Status : UP")
 } else {
 fmt.Println("Status : DOWN")
 }

 if strings.Contains(i.Flags.String(), "multicast") {
 fmt.Println("Support multicast : YES")
 } else {
 fmt.Println("Support multicast : NO")
 }
 }

 }

Sample output :

Name : lo0

Interface type and supports : up|loopback|multicast

Status : UP

Support multicast : YES

Name : gif0

Interface type and supports : pointtopoint|multicast

Status : DOWN

Support multicast : YES

Name : stf0

Interface type and supports : 0

Status : DOWN

Support multicast : NO

Name : en1

Interface type and supports : up|broadcast|multicast

Status : UP

Support multicast : YES

See Also : https://www.socketloop.com/references/golang-net-ip-isloopback-ismulticast-and-isunspecified-functions-example

References :

http://golang.org/pkg/net/#Interfaces

http://golang.org/pkg/net/#Flags

 const (
 FlagUp Flags = 1 << iota // interface is up
 FlagBroadcast // interface supports broadcast access capability
 FlagLoopback // interface is a loopback interface
 FlagPointToPoint // interface belongs to a point-to-point link
 FlagMulticast // interface supports multicast access capability
 )

https://www.socketloop.com/references/golang-net-flags-type-and-flags-string-function-example