Wda is running on my localip:8100, but appium failed to connect

I’m using appium 2.0.0 --beta 12.
When i test the ios app on real device, the appium will first build a wda agent with xcode. From the xcode log i can see the build is successful and the wda is listening on, and if i can get 200 ok on the browser, but i can’t open the page with from browser.
If i run “iproxy 8100 8100”, it will work.
Please help, many thanks.