/usr/sbin/ifconfig -a
...
lo0: flags=2002000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv6,VIRTUAL> mtu 8252 index 1
        inet6 ::1/128 
net0: flags=120002000841<UP,RUNNING,MULTICAST,IPv6,PHYSRUNNING> mtu 1500 index 2
        inet6 fe80::221:28ff:feb3:20f2/10 
net0:1: flags=120002080841<UP,RUNNING,MULTICAST,ADDRCONF,IPv6,PHYSRUNNING> mtu 1500 index 2
        inet6 2620:52:0:105f:221:28ff:feb3:20f2/64 
net4: flags=120002000840<RUNNING,MULTICAST,IPv6,PHYSRUNNING> mtu 1500 index 3
        inet6 ::/0

expected:</2620:52:0:105f:221:28ff:feb3:20f2%2> but was:<null>

java.lang.AssertionError: expected:</2620:52:0:105f:221:28ff:feb3:20f2%2> but was:<null>
	at org.junit.Assert.fail(Assert.java:88)
	at org.junit.Assert.failNotEquals(Assert.java:743)
	at org.junit.Assert.assertEquals(Assert.java:118)
	at org.junit.Assert.assertEquals(Assert.java:144)
	at org.jboss.as.controller.interfaces.IPv6ScopeIdMatchUnitTestCase.testNonLoopback(IPv6ScopeIdMatchUnitTestCase.java:129)

Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements()) {
    NetworkInterface nic = interfaces.nextElement();
    Enumeration<NetworkInterface> subInterfaces = nic.getSubInterfaces();
    while (subInterfaces.hasMoreElements()) {
        NetworkInterface subInterface = subInterfaces.nextElement();
        System.out.println(subInterface.getName());
        System.out.println(NetworkInterface.getByName(subInterface.getName()));
    }
}

em1:0
null