Connect to local network with OpenVPN . Problem: Local IP address unset but adding route?

Question

The goal

I do want to connect to some services (e.g. file server, IP camera etc) in my home network from my mobile phone by using VPN. I use Tomato Version 1.28 (shibby) on my Netgear WNR3500L v2 Router and I set up an OpenVPN server following the instructions here.

The Problem

I then try to connect my OPO with Cyanogenmod 11.0 based on Android 4.4.4 by using the OpenVPN client. The handshake seems to work okay but then I receive the following error message on my phone in the OpenVPM app:

[...]
2014-09-25 21:09:07 MANAGEMENT: CMD 'needok 'ROUTE' ok'
2014-09-25 21:09:07 Local IP address unset but adding route?! This broken! Please contact author with log
2014-09-25 21:09:07 Open tun network interface:
2014-09-25 21:09:07 Refusing to open tun device without IP information
2014-09-25 21:09:07 MANAGEMENT: CMD 'needok 'OPENTUN' cancel'
2014-09-25 21:09:07 MANAGEMENT: Client disconnected
2014-09-25 21:09:07 ERROR: Cannot open TUN

The server log says:

Sep 25 21:28:29 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 TLS: new session incoming connection from [AF_INET]11.22.33.44:7066
Sep 25 21:28:30 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 VERIFY OK: depth=1, C=AU, ST=ACity, L=ACity, O=Private, OU=changeme, CN=ACity.mooo.com, name=changeme, [email protected]
Sep 25 21:28:30 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 VERIFY OK: depth=0, C=AU, ST=ACity, L=ACity, O=Private, OU=changeme, CN=carl, name=carl, [email protected]
Sep 25 21:28:30 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key
Sep 25 21:28:30 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Sep 25 21:28:30 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 Data Channel Decrypt: Cipher 'BF-CBC' initialized with 128 bit key
Sep 25 21:28:30 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Sep 25 21:28:30 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 TLS: move_session: dest=TM_ACTIVE src=TM_UNTRUSTED reinit_src=1
Sep 25 21:28:30 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 TLS: tls_multi_process: untrusted session promoted to semi-trusted
Sep 25 21:28:30 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 1024 bit RSA
Sep 25 21:28:32 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 PUSH: Received control message: 'PUSH_REQUEST'
Sep 25 21:28:32 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 send_push_reply(): safe_cap=940
Sep 25 21:28:32 unknown daemon.notice openvpn[3842]: carl/11.22.33.44:7066 SENT CONTROL [carl]: 'PUSH_REPLY,dhcp-option DNS 192.168.0.1,route-gateway 192.168.0.1,redirect-gateway def1,route-gateway dhcp,ping 15,ping-restart 60' (status=1)

Question

What does this error message mean

Local IP address unset but adding route?!

What setting am i missing? Why can't I connect to my home network via VPN?

Answer 1

I managed to resolve what I think was the same issue as you (I am also using Shibby firmware for OpenVPN and using an Android client).

I believe it comes down to how the routes are pushed to the client and the Android app not liking it (the refusal to open tun interface is an error message belonging to the app).

I'm not sure why the routes aren't pushed successfully, but if you set up your client profile under IP and DNS, disable Pull Settings and set the IPv4 address to be the same network/cidr as whatever bridge your TAP OpenVPN interface is (default is br0 and 192.168.1.0/24).

This also even gives me internet access over the router.

Note I'm using the latest versions of the Android app and Shibby firmware as of writing.