[edermann]

I'm a German student living temporarily in Australia. I would like to stream German TV (from ARD Mediathek and other places) to my Chromecast at my TV. As this is geoblocked in Australia, I thought that the best solution will be to install DD-WRT on my Router and then connect to my German University via OpenVPN.

1) I succeeded in installing DD-WRT on my Netgear R6400v2 Router.
2) I also succeeded in connecting to my university VPN and I can stream on my computer.
3) I used the TUN setting with NAT enabled. I'm attaching my OpenVPN configuration.

4) HOWEVER, if I try to cast any video (on ARD Mediathek or even just Youtube) to my Chromecast, it fails. In Chrome, it just says "Casting failed. Try again later".
5) If I disconnect the VPN, I can cast Youtube videos without problems, but then ARD Mediathek is geoblocked.
6) I also tried to use TAP with bridging, where casting to my Chromecast worked, but the traffic was not routed through the VPN (IP location was still shown to be in Australia and I could not stream geoblocked content).

Any ideas what I'm doing wrong?

[dale_gribble39]

Is this on 54604?

https://ftp.dd-wrt.com/dd-wrtv2/downloads/betas/2023/12-26-2023-r54604/netgear-r6400v2/

Is your router the OTP version?

https://ftp.dd-wrt.com/dd-wrtv2/downloads/betas/2023/12-26-2023-r54604/netgear-r6400v2otp/

Are you sure your University isn't blocking Chromecast?

[edermann]

Thank you so much for your reply!

Regarding your question:
- Yes, I am using the OTP version. I installed DD-WRT v3.0-r47479 std (09/23/21) because that was the recommended version in the installation guide for my device.
- I am not sure if my university blocks Chromecast. Is there an easy check that I could do?

[edermann]

Ok, another update.

In order to test my router functionality, I now tested the OpenVPN setup with another VPN, namely the free version of ProtonVPN where I could connect to a US server. My OpenVPN configuration worked and I found the following:
- All relevant traffic was routed to the US and when checking my IP location, it showed a US location.
- I could now stream Youtube etc. from my Laptop to my Chromecast device.

Based on this finding, I assume that
(a) either my university is indeed blocking relevant ports for Chromecast (question: could I choose to route specific traffic not through the VPN, but hopefully only the traffic needed for unblocking geoblocked content - this may be possible, as I can stream geoblocked content on my laptop, so my university does not seem to block the relevant traffic for unblocking),
(b) or I made some mistake in my configuration, such that my OpenVPN blocks (!?) something relevant for Google Chromecast...

I welcome any ideas/suggestions. Again thank you so much for any help!

[dale_gribble39]

Upgrade. Installation is just to get the firmware installed, you may still require upgrading, especially since there has been TONS of development regarding OpenVPN since that build.

Also, look up "Chromecast DD-WRT". There may be relevant or irrelevant information in a wiki or forum thread or elsewhere.

[edermann]

Thank you again for your response.

I updated to the current version of DD-WRT, but the problem still persists.

It is interesting: I can actually screencast my smartphone to Chromecast (I could do this before, too), but not an external stream (e.g., Youtube etc.), where it just says that casting failed.

I already tried the forum search function (OpenVPN + Chromecast) and searched the general web (DD-WRT + OpenVPN + Chromecast), but I could not find anybody with a similar problem.

Clearly, the VPN works, but somehow blocks some part of Chromecast that is crucial for using the casting functionality. However, I wouldn't even know how to check what specifically is blocked...

My hope would be that the streaming content itself is not blocked (as I can stream this on my regular computer without problems), but rather something else. Now the question would be if this something else could be routed outside of the VPN to make casting work, but I'm completely new to DD-WRT and wouldn't know where to start.

[lexridge]

Google, YouTube, whatever does have VPN detection. I see this all the time with YouTubeTV. It could be part of your problem but maybe not. Perhaps they only use it for YouTubeTV and the reasons are extremely complicated...mostly dealing with FCC blackout requirements and local/regional networks.

[edermann]

Maybe yet another question:

I found in the Wiki (https://forum.dd-wrt.com/wiki/index.php/Google_Chromecast) that one should add the Firewall commands

iptables -I FORWARD --destination 8.8.8.8 -j REJECT
iptables -I FORWARD --destination 8.8.4.4 -j REJECT

to access the Google Public DNS Servers for Chromecast.

Clearly, in my case this is not necessary if I don't use VPN, but maybe that gives a hint what may be potentially be blocked. Would there be a way to route communication with those IP addresses outside of the OpenVPN tunnel?

[lexridge]

Have you tried using Wireguard instead of OpenVPN?

[edermann]

Hi lexridge, Thank you so much for the question.

I have not tried Wireguard, because I didn't know WireGuard and my university only offers OpenVPN. However, when I just looked it up, I assume you mean that it should be possible to use WireGuard (using dd-wrt Setup -> Tunnels as explained here: https://support.surfshark.com/hc/en-us/articles/7161303618834-How-to-set-up-WireGuard-on-a-DD-WRT-router) to connect to the OpenVPN server?

I will try this and see how far I get.

I don't quite understand difference / pro & cons of WireGuard vs. OpenVPN if both connects to an OpenVPN server.

Either way, thank you for any ideas/suggestions that I can try. I will report if I make any progress...

[lexridge]

[edermann]

I see. I just tried to setup a WireGuard Tunnel, but I don't how to connect with the OpenVPN server from my university. Do you have any suggestions where I can read more about this?

It already starts that the WireGuard Tunnel on the dd-wrt GUI does not ask me for my OpenVPN server domain, my username or password. How can I connect it?

Sorry for those naive questions!

[lexridge]

I don't think Wireguard will connect to an OpenVPN server. If your University only uses OVPN then I would say you are stuck with using that.

[edermann]

Thank you everybody.

I tested free VPN services, starting with ProtonVPN, which doesn't offer a German location in its free version, but at least I could confirm that everything worked, as soon as I used them (i.e., I got a US IP and I could stream Youtube to Chromecast). This confirmed that the problem must be some type of blocking in the OpenVPN provided by my German university. Very unfortunate.

I then tested hide.me free OpenVPN, where they gave me a 5 day free (no credit card needed) trial subscription, where I could use OpenVPN at a German location and everything worked perfectly.

However, as hide.me does not allow manual configuration for free users, I looked for other services and found vpnjantit.com. While the website looks sketchy, they do provide German OpenVPN (and also Wireguard) servers for free, where one always gets login information valid for 4-7 days or so. I set this up and it works well for my purpose, as I will only occasionally watch German TV on my Chromecast.

So I'm happy with this solution.