• I have searched the issues of this repository and believe that this is not a duplicate.
• I have checked the FAQ of this repository and believe that this is not a duplicate.

Environment

• Dubbo version: master branch
• Operating System version: macOS 10.13.6
• Java version: 1.8

Step to reproduce this issue

1. start the provider demo

Expected Result

Provider start success.

Actual Result

Provider start failed.

If there is an exception, please attach the exception trace:

Caused by: java.net.SocketException: Can't assign requested address
	at java.net.PlainDatagramSocketImpl.join(Native Method)
	at java.net.AbstractPlainDatagramSocketImpl.join(AbstractPlainDatagramSocketImpl.java:178)
	at java.net.MulticastSocket.joinGroup(MulticastSocket.java:323)
	at org.apache.dubbo.registry.multicast.MulticastRegistry.<init>(MulticastRegistry.java:91)
	... 24 more

If I add vm args -Djava.net.preferIPv4Stack=true, everything works fine.