AC3200, R8000 does not support "dev tun"

Thank You.

Here is the client debug log and it clearly points out the failure reason.

2017-04-26 10:52:46 SSL Handshake: TLSv1.0/TLS-DHE-RSA-WITH-3DES-EDE-CBC-SHA
2017-04-26 10:52:46 Session is ACTIVE
2017-04-26 10:52:46 EVENT: GET_CONFIG
2017-04-26 10:52:46 Sending PUSH_REQUEST to server...
2017-04-26 10:52:46 NET Internet:ReachableViaWWAN/WR t------
2017-04-26 10:52:46 OPTIONS:
0 [route] [192.168.0.1] [255.255.255.0]
1 [route-delay] [5]
2 [redirect-gateway] [def1]
3 [route-gateway] [dhcp]
4 [ping] [10]
5 [ping-restart] [120]

2017-04-26 10:52:46 PROTOCOL OPTIONS:
  cipher: AES-128-CBC
  digest: SHA1
  compress: LZO
  peer ID: -1
2017-04-26 10:52:46 EVENT: ASSIGN_IP
2017-04-26 10:52:46 TUN Error: tun_prop_error: one of ifconfig or ifconfig-ipv6 must be specified
2017-04-26 10:52:46 EVENT: TUN_SETUP_FAILED tun_prop_error: one of ifconfig or ifconfig-ipv6 must be specified [ERR]
2017-04-26 10:52:46 EVENT: DISCONNECTED
2017-04-26 10:52:46 Client exception in transport_recv: tun_exception: not connected
2017-04-26 10:52:46 Raw stats on disconnect:
  BYTES_IN : 3498
  BYTES_OUT : 2619
  PACKETS_IN : 35
  PACKETS_OUT : 35
  TUN_SETUP_FAILED : 1
2017-04-26 10:52:46 Performance stats on disconnect:
  CPU usage (microseconds): 79480
  Network bytes per CPU second: 76962
  Tunnel bytes per CPU second: 0
2017-04-26 10:52:46 EVENT: DISCONNECT_PENDING
2017-04-26 10:52:46 ----- OpenVPN Stop -----