title: Android 4 OpenVPN App tun_builder_error (topology net30)
body: <p>I've running an OpenVPN server on my server and I want to connect several devices (smartphone, notebooks, desktop computers, tablets...). I have no problem connecting notebooks with Linux or Mac OS X or my Windows 8 tablet. So that work's pretty well.</p>
  
  <p>But when I want to connect my Nexus 5 with Android 4.4.2, the OpenVPN app gives me the following error:</p>
  
  <pre><code>12:53:32.106 -- EVENT: TUN Error: tun_builder_error: ifconfig addresses are not in the same /30 subnet (topology net30)
  </code></pre>
  
  <p>Here is my client.conf.:</p>
  
  <pre><code>client
  dev tun
  proto udp
  remote xx.xx.xx.xx 1194
  resolv-retry infinite
  nobind
  user nobody
  group nogroup
  persist-key
  persist-tun
  
  ca ca.crt
  cert Nexus5.crt
  key Nexus5.key
  
  ns-cert-type server
  
  comp-lzo
  verb 3
  pull
  </code></pre>
  
  <p>And the corresponding server.conf:</p>
  
  <pre><code>script-security 2
  port 1194
  proto udp
  dev tun
  
  ca ca.crt
  cert server.crt
  key server.key
  dh dh1024.pem
  
  server 10.8.0.0 255.255.255.0
  ifconfig-pool-persist ipp.txt
  push "route 10.8.0.0 255.255.255.0"
  client-config-dir ccd
  
  push "redirect-gateway def1"
  
  push "dhcp-option DNS 208.67.220.220"
  up ./up-script.sh
  down ./down-script.sh
  
  client-to-client
  keepalive 10 120
  
  comp-lzo
  
  user nobody
  group nogroup
  
  persist-key
  persist-tun
  
  status openvpn-status.log
  log         openvpn.log
  verb 3
  </code></pre>
  
  <p>The ccd/Nexus5 file:</p>
  
  <pre><code>ifconfig-push 10.8.0.11 255.255.255.0
  </code></pre>
  
  <p>I use the same client.conf for every client (adapted certificates of course). It work's on every device, except the Nexus 5. After research I read that it might help adding</p>
  
  <pre><code>push "topology subnet"
  </code></pre>
  
  <p>to the server.conf. But then no client can connect anymore, so that doesn't help.
  Can you spot any error in my config files or anything?</p>
  
  <p>Here is the log from the Nexus 5 OpenVPN app:</p>
  
  <pre><code>12.53.30.522 -- ---- OpenVPN Start ----
  12.53.30.523 -- EVENT: CORE_THREAD_ACTIVE
  12.53.30.531 -- UNUSED OPTIONS
  4 [resolv-retry] [infinite]
  5 [nobind]
  6 [user] [nobody]
  7 [group] [nogroup]
  8 [persist-key]
  9 [persist-tun]
  15 [verb 3]
  16 [pull]
  
  12:53:30:531 -- EVENT: RESOLVE
  12:53:30.534 -- LZO-ASYM init swap=0 asym=0
  12:53:30.534 -- Contacting xx.xx.xx.xx:1194 via UDP
  12:53:30.535 -- EVENT: WAIT
  12:53:30.537 -- Connecting to xx.xx.xx.xx:1194 via UDPv4
  12:53:30.572 -- EVENT: CONNECTING
  12:53:30.575 -- Tunnel Options:V4,dev-type tun,link-mtu 1542,tun-mtu 1500,proto UDPv4,comp-lzo,cipher BF-CBC,auth SHA1,keysize 128,key-method 2,tls-client
  12:53:30.775 -- Peer Info:
  IV_GUI_VER=net.oopenvpn.connect.android
  1.1.13-53
  IV_VER=3.0
  IV_PLAT=android
  IV_NCP=1
  IV_LZO=1
  
  12:53:30.779 -- VERIFY OK: depth=1
  ..
  12:53:30.780 -- VERIFY OK: depth=0
  ..
  12:53:31.121 -- SSL Handshake: TLSv1.0/TLS-DHE-RSA-WITH-AES-256-CBC-SHA
  12:53:31.122 -- Session is ACTIVE
  12:53:31.123 -- EVENT: GET_CONFIG
  12:53:31.130 -- Sending PUSH_REQUEST to server...
  12:53:31.165 -- OPTIONS:
  0 [route] [10.8.0.0] [255.255.255.0]
  1 [redirect-gateway] [def1]
  2 [dhcp-option] [DNS] [208.67.220.220]
  3 [route] [10.8.0.0] [255.255.255.0]
  4 [topology] [net30]
  5 [ping] [10]
  6 [ping-restart] [120]
  7 [ifconfig] [10.8.0.11] [255.255.255.0]
  
  12:53:31.166 -- LZO-ASYM init swap=0 asym=0
  12:53:31.167 -- EVENT: ASSIGN_IP
  12:53:31.177 -- TUN Error: tun_builder_error: ifconfig addresses are not on the same /30 subnet (topology 30)
  12:53:31.181 -- EVENT: TUN_SETUP_FAILED
  info='tun_builder_error: ifconfig addresses are not on the same /30 subnet (topology 30)'
  12:53:31.188 -- EVENT: DISCONNECTED
  12:53:31.198 -- EVENT: CORE_THREAD_INACTIVE
  12:53:31.199 -- Tunnel bytes per CPU second: 0
  12:53:31.200 -- ---- OpenVPN Stop ----
  </code></pre>
  
  <p>Thank you!</p>