title: Kubernetes not preserve source ip
body: <p>I've installed kubernetes 1.2.0 with the following configuration</p>
  
  <pre><code>export nodes="user@10.0.0.30 user@10.0.0.32"
  export role="ai i"
  export NUM_NODES=2
  export SERVICE_CLUSTER_IP_RANGE=192.168.3.0/24
  export FLANNEL_NET=172.16.0.0/16
  export KUBE_PROXY_EXTRA_OPTS="--proxy-mode=iptables"
  </code></pre>
  
  <p>I've created a nginx pod and expose with load balancer and external IP address</p>
  
  <pre><code>kubectl expose pod my-nginx-3800858182-6qhap --external-ip=10.0.0.50 --port=80 --target-port=80
  </code></pre>
  
  <p>I'm using kubernetes on bare metal so i've assigned 10.0.0.50 ip to master node.</p>
  
  <p>If i try curl 10.0.0.50 (from outside kubernetes) and use tcpdump on nginx pod i see traffic, the source ip is always from the kubernetes master node</p>
  
  <pre><code>17:30:55.470230 IP 172.16.60.1.43030 &gt; 172.16.60.2.80: ...
  17:30:55.470343 IP 172.16.60.2.80 &gt; 172.16.60.1.43030: ...
  </code></pre>
  
  <p>i'm using mode-proxy=iptables. and need to get the actual source ip. what am i doing wrong ?</p>