Setting up Raspberry Pi as an OpenVPN client for the NETGEAR R7000 Nighthawk router

Since OpenVPN isn’t too chatty about failures in its default configuration, this took me a couple of tries to get right. Hopefully this post can save you some of the time I wasted .

In the following example, I’m assuming you already have a Raspberry Pi, running Raspbian and that you can access it over the local network. From the snippets below, change the example ip 192.168.3.14, to the ip of your local device.

Router

Start off by enabling the vpn service on the router, by going to ADVANCED > Advanced Setup > VPN Service, then check off Enable VPN Service and then click Apply.

When that is done and the router has rebooted, go back to the same page and download the VPN configuration zip file, nonwindows.zip, and copy it to the Pi:

rene $ scp nonwindows.zip pi@192.168.3.14:

Pi

Log in to the Pi and set up OpenVPN:

rene $ ssh pi@192.168.3.14
pi:~$ sudo apt-get update && sudo apt-get install openvpn

Once the installation is complete, add the configuration to openvpn:

pi:~$ unzip nonwindows.zip
pi:~$ sudo cp client2.conf ca.crt client.crt client.key /etc/openvpn/
pi:~$ sudo chown root:root /etc/openvpn/{client2.conf,ca.crt,client.crt,client.key}
pi:~$ sudo chmod 600 /etc/openvpn/{client2.conf,ca.crt,client.crt,client.key}
pi:~$ ls -la /etc/openvpn/
total 28
drwxr-xr-x  2 root root 4096 Jul 13 14:13 .
drwxr-xr-x 70 root root 4096 Jul 13 14:44 ..
-rw-------  1 root root 1253 Jul 13 13:57 ca.crt
-rw-------  1 root root 3576 Jul 13 13:57 client.crt
-rw-------  1 root root  891 Jul 13 13:57 client.key
-rw-------  1 root root  180 Jul 13 13:57 client2.conf
-rwxr-xr-x  1 root root 1301 Nov 19  2015 update-resolv-conf

Assuming you’re the only one accessing this Pi, setting the owner and file permissions isn’t strictly necessary, but nevertheless good practice. There’s no reason the these files should be readable by anyone but root.

Next you should edit /etc/default/openvpn and add a directive for the new configuration to start on boot:

AUTOSTART="client2"

Now reboot the Pi and verify that a new network device has been added for the remote network:

pi:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr b8:27:eb:1c:fa:81
          inet addr:10.0.0.4  Bcast:10.0.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST DYNAMIC  MTU:1500  Metric:1
          RX packets:4228 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1781 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:820993 (801.7 KiB)  TX bytes:246368 (240.5 KiB)
 
lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:13 errors:0 dropped:0 overruns:0 frame:0
          TX packets:13 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:1320 (1.2 KiB)  TX bytes:1320 (1.2 KiB)
 
tap0      Link encap:Ethernet  HWaddr da:dd:3a:80:50:7c
          inet addr:192.168.1.7  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST DYNAMIC  MTU:1500  Metric:1
          RX packets:621 errors:0 dropped:0 overruns:0 frame:0
          TX packets:177 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:70344 (68.6 KiB)  TX bytes:15922 (15.5 KiB)

Et voilà, that should be all there is to it!

Addendum

In case something didn’t quite go as planned, enabling some logging might be a good idea. Here’s a filtered list of options related to logging:

pi:~$ openvpn --help | grep log
--topology t    : Set --dev tun topology: 'net30', 'p2p', or 'subnet'.
                  as the program name to the system logger.
--syslog [name] : Output to syslog, but do not become a daemon.
--log file      : Output log to file which is created/truncated on open.
--log-append file : Append log to file, or create file if nonexistent.
--suppress-timestamps : Don't log timestamps to stdout/stderr.
--echo [parms ...] : Echo parameters to log output.
--management-log-cache n : Cache n lines of log file history for usage
--mute-replay-warnings : Silence the output of replay warnings to log file.
--pkcs11-cert-private [0|1] ... : Set if login should be performed before

To make use of one of these options, it used to be that the parameters could be passed in the OPTARGS directive of /etc/default/openvpn, but since OpenVPN has moved to using systemd, this is no longer supported. Relevant bug report.

Instead it is necessary to set them directly in each configuration. E.g. to enable append logging to a file add, edit /etc/openvpn/client2.conf and add the following line:

log-append /var/log/openvpn.log

According the the man page verbosity is set from 0-11, and by default the vpn configuration from the R7000 has verbosity set to 5. This means the log file can quickly become rather large if left in append mode unattended, so make sure you have enough room on the SD card or remove the option again, when you are done debugging. Alternatively use –management-log-cache or truncate on each run by just using –log.

N.B. In my experience the client can be a bit flaky at times and I’ve often seen the first many connection attempts end in the following errors:

TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
TLS Error: TLS handshake failed

And then after a number of tries, suddenly come through. Don’t ask me why.

14 thoughts on “Setting up Raspberry Pi as an OpenVPN client for the NETGEAR R7000 Nighthawk router

  1. Hello and thanks for your instructions, however I’m not getting any new network device. The only thing I can see that is different from yours is this sentence:
    drwxr-xr-x 70 root root 4096 Jul 13 14:44 ..
    I’m getting 85 not 70. Do you have any clues?

    • Hi Yngve,

      That number is just the number of hard links in the filesystem, for the parent directory “..”, so that shouldn’t have any significance in this context.

      Have you tried increasing the log level and taking a look in /var/log/openvpn.log?

      Perhaps there’s some error message in the log, that could further clue in on what might be the issue.

  2. Thanks for the swift response! As you probably know by now, I’m a newbie in linux, but I will try to delve into the logs 🙂

    • I took the liberty of moving the log output to pastebin. Easier to read from there, than these comment boxes. 🙂

      I’m not sure it’ll make much of a difference, but the DNS resolution errors for skog.mynetgear.com, could be fixed by replacing the domain with the corresponding ip in the configuration file.

      You should have a line in client2.conf:

      remote skog.mynetgear.com 12974

      You could try changing to:

      remote 46.9.29.72 12974

      In order to avoid the DNS lookup. Besides that looks like packets are being dropped going to the router:

      RMon Oct  9 14:22:37 2017 us=476540 TCP/UDP: Incoming packet rejected from [AF_INET]192.168.1.1:12974[2], expected peer address: [AF_INET]46.9.29.72:12974 (allow this incoming source address/port by removing --remote or adding --float)
      

      Are you by any chance trying to connect the VPN, while the Raspberry Pi is physically on the local-network of the same router?

      This I’ve never been able to do myself. The VPN client just wouldn’t connect, from my laptop e.g., if I tried to connect while on the same network, as I was trying to connect to. Which of course wouldn’t make much sense either… 🙂

      If you’re doing the setup at home first and then moving the Raspberry Pi to it’s destination network afterwards, you can try doing it over a hotspot from your phone e.g. to get an external connection, inwards to the router on the WAN side.

  3. Thanks! The first issue you are referring, the ip-address, I think was just that I hadn’t confirmed the dyndns service. I was looking at the log after having made this confirmation and now I can’t see this error anymore. Regarding the last issue I haven’t been trying at all to connect to the vpn client.
    But don’t you think that the fact that I don’t have this extra network device, Tap0, is related to the problem?

    • That is definitely a sign that something is wrong. However, and I don’t know this for sure, I don’t think you’ll see neither a tun or tap virtual device, before a successful connection is actually made to the VPN server.

  4. Just want to let you know that your manual is working great! I hadn’t installed the client on the phone, so it was actually working all the time 🙂 Thanks again!

  5. One final question in trying to understand the client/server relation. Now the openvpn server is on my router and I have a client on my Raspberry and it connects well. Then in my head if I was supposed to reach my surveillance cameras, my NAS server, my Plex server and so on, I would need to install a openvpn client on each of these as well, but that is not the case. I’m able to reach all of them without client installation. Is this how it’s supposed to be, or do I have a major security flaw in my LAN?

    • You don’t have a security flaw. That’s the beauty of how a VPN works. It “bridges” your client into the existing network. The way to think of it, is as if you had physically plugged your Raspberry Pi into the local network it connects to over VPN.

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