text: Title: kube-proxy: node-port ipv6 port open on v4 cluster 
  Body: /kind bug
  
  
  **What happened**:
  
  When creating a node port application (in this case the example guestbook) on a host server that is dual stacked and has AAAA and A DNS entries, the node port on the v6 address is open to kube-proxy and hangs. 
  
  **What you expected to happen**:
  
  The v6 address would refuse the connection and the client would fall back onto the v4 address which would connect correctly.
  
  **How to reproduce it (as minimally and precisely as possible)**:
  
  ```
  apiVersion: kubeadm.k8s.io/v1alpha2
  kind: MasterConfiguration
  clusterName: kubernetes
  api:
    advertiseAddress: <ipv4 address>
  networking:
    dnsDomain: cluster.local
    podSubnet: 192.168.0.0/16
    serviceSubnet: 172.30.0.0/16
  bootstrapTokens:
    - token: v315ij.jrg9nu08ayho78q7
  kubeProxy:
    config:
      mode: ipvs
      ipvs:
        scheduler: lc
  ```
  
  kubeadm init with the above, and join in some workers. Then install the guestbook application https://kubernetes.io/docs/tutorials/stateless-application/guestbook/
  
  Obtain the node port with `kubectl get services frontend` and telnet to one of the servers on that port from a dual stacked client. The client will connect and refuse to respond to 'GET /'
  
  telnet directly to the IPv4 address of the server on the port and all works as expected. 
  
  **Anything else we need to know?**:
  
  kube-proxy is noted as listening on the port. 
  
  ```
  ubuntu@srv-jidtj:~$ sudo ss -l -t -p | grep 31759
  LISTEN   0         128                       *:31759                   *:*       users:(("kube-proxy",pid=2268,fd=7))
  ```
  
  
  **Environment**:
  - Kubernetes version (use `kubectl version`):
  ubuntu@srv-jidtj:~$ kubectl version
  Client Version: version.Info{Major:"1", Minor:"11", GitVersion:"v1.11.1", GitCommit:"b1b29978270dc22fecc592ac55d903350454310a", GitTreeState:"clean", BuildDate:"2018-07-17T18:53:20Z", GoVersion:"go1.10.3", Compiler:"gc", Platform:"linux/amd64"}
  Server Version: version.Info{Major:"1", Minor:"11", GitVersion:"v1.11.1", GitCommit:"b1b29978270dc22fecc592ac55d903350454310a", GitTreeState:"clean", BuildDate:"2018-07-17T18:43:26Z", GoVersion:"go1.10.3", Compiler:"gc", Platform:"linux/amd64"}
  - Cloud provider or hardware configuration:
  Brightbox
  - OS (e.g. from /etc/os-release):
  Ubuntu 18.04.1 LTS
  - Kernel (e.g. `uname -a`):
  Linux srv-jidtj 4.15.0-29-generic #31-Ubuntu SMP Tue Jul 17 15:39:52 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
  - Install tools:
  kubeadm 1.11
  - Others:
  