Chromecast/MiraCast/WiDi on a subnetted device?

banie01

I've got an issue that I am starting to think may be a NAT issue but I'm hoping that someone can give me a steer.

My network setup is currently fibre ONT as modem with an ASUS RT-AX88U as the primary router serving the house. I have a 2nd Asus modem wired back to the main router as an AP in an outbuilding. So Ont > Asus main > Asus AP.

The outbuilding AP works great no issues and 1gb throughput.

Now onto my issue. I have a Philips Smart TV in the outbuilding that I wish to cast my laptop to. Initially the TV was connected to ethernet. Searching for display on the laptop failed. A little Google fu led me to believe that both cast devices, sender and receiver have to be on the same WiFi network.

So 2nd attempt was to switch off TV ethernet and connect both TV and Laptop to AP WiFi. That failed to find the display too.

Laptop will cast to main TV in the house and other Chromecast in main house connected to "main" router.

This is leading me to think that the issue in the outbuilding is possibly a double NAT issue?

If anyone has tips on how I might mitigate that? Or indeed if anyone has another idea as to what I can try?

Fire away.

smuggler.ie

Can you confirm 2nd Asus router is in "AP mode". There would be no NAT(as well as no DHCP, no firewall) on it if it is.

Also try to disable IPv6 on main router DHCP

Edit:

Now onto my issue. I have a Philips Smart TV in the outbuilding that I wish to cast my laptop to. Initially the TV was connected to ethernet. Searching for display on the laptop failed. A little Google fu led me to believe that both cast devices, sender and receiver have to be on the same WiFi network.

One network, is not specificaly WiFi, ... as long is one network

banie01

https://www.boards.ie/discussion/comment/120320816#Comment_120320816

Yep, in AP mode with DHCP & firewall handled by the main router. I'll give the IPv6 a check when I get home.

smuggler.ie

any luck?

banie01

https://www.boards.ie/discussion/comment/120331568#Comment_120331568

Ipv6 is disabled and I'm still no closer to getting it to work.

smuggler.ie

WiFi client isolation turned off?, asus call it "AP isolated".

banie01

https://www.boards.ie/discussion/comment/120333132#Comment_120333132

My NAS is plugged into the 2nd Asus and if memory serves enabling isolation will mean that any wireless devices won't connect?

smuggler.ie

https://www.boards.ie/discussion/comment/120334319#Comment_120334319

Not knowing your setup, just asking.

Would NAS be accessible on LAN behind double NAT'ed unit? I think not - unless i am wrong, double NAT version also out the window.

Access to NAS would be tested from main router (right?) where, as you say, isolation is off. Worth to check 2nd for same

Isolation has to be OFF on both Asus'es as they form separate WiFi networks, just with same SSID/pass(am i right here?). I guess, for this setup, your laptop is connected to 2nd as well as TV.

Can you "see" NAS on the laptop when connected to 2nd asus WiFi , or other network devices, or can you cast to other TV's you could before? For clearance, you could change 2nd SSID/pass temporaraly so you know what asus wifi you are connected.

My samsung tv show-up on the list of availble screens on laptop, even two them are on two physically independant networks. Laptop was never even connected to "main" WiFi (fecking "neighbour sniffers"!) Failing to connect obviously

10-10-20

So this isn't "subnetted" and it's not NATed - all devices are on a flat network range - right? For example: all IP's on the range of 192.168.0.1 to 192.168.0.254 with a subnet mask of 255.255.255.0 and the gateway set as the IP of the main router? DNS should also point at the main router or an external device. The devices should also be time synced (NTP) to the router or an external NTP pool.

Casting uses mDNS which is server-less discovery protocol so that has to be working properly, but the best test that I can find is by running avahi discovery off a Linux system (you do have a linux system, right...?)

https://developers.google.com/cast/docs/discovery

10-10-20@Inspiron-15:~$ avahi-discover 
Browsing domain 'local' on -1.-1 ...
Browsing for services of type '_spotify-social-listening._tcp' in domain 'local' on 2.1 ...
Browsing for services of type '_nut._tcp' in domain 'local' on 2.1 ...
Browsing for services of type '_spotify-social-listening._tcp' in domain 'local' on 2.0 ...
Browsing for services of type '_esphomelib._tcp' in domain 'local' on 2.0 ...
Browsing for services of type '_shelly._tcp' in domain 'local' on 2.0 ...
Browsing for services of type '_http._tcp' in domain 'local' on 2.0 ...
Browsing for services of type '_nut._tcp' in domain 'local' on 2.0 ...
Found service 'Spotify Group Session [2rKNF]' of type '_spotify-social-listening._tcp' in domain 'local' on 2.1.
...
Browsing for services of type '_airplay._tcp' in domain 'local' on 2.0 ...
Browsing for services of type '_spotify-connect._tcp' in domain 'local' on 2.0 ...
Browsing for services of type '_bose-passport._tcp' in domain 'local' on 2.0 ...
Browsing for services of type '_raop._tcp' in domain 'local' on 2.0 ...

Try that if you can otherwise you may need to workout how to do a similar discovery from Windows. 🙄

banie01

https://www.boards.ie/discussion/comment/120336065#Comment_120336065

Thanks for the breakdown. NAS is visible when both laptop and NAS are connected to 2nd router (and checked to ensure its both on 2nd router, in the outbuilding and with WiFi disabled on 1st).

Isolation is off on both routers. I will spend a bit of time out there tmrw troubleshooting properly.

https://www.boards.ie/discussion/comment/120337671#Comment_120337671

I can boot into a usb install and give the Linux script a try. Thanks for the detailed info.

smuggler.ie

DNS should also point at the main router

good point here, worth attention, still : "Laptop will cast to main TV in the house and other Chromecast in main house connected to "main" router."

Without digging deep , with NAS available, WiFi OK, etc... seams like issue with TV alone. Does it even support screen share ?

banie01

https://www.boards.ie/discussion/comment/120338291#Comment_120338291

TV has Chromecast built-in, I'll update the thread tmrw on how it goes.

banie01

Still no joy in getting the laptop to connect. TV is visible in network explorer and what's even more irritating is that I can cast from Android devices to TV.

I get held up with medical stuff today so haven't got around to giving 10-10-20's suggestion a try but, will endeavour to get it done after the early game tmrw 😉

The yoke has me stumped for now, but especially as Android cast works. If I can't sort it over the weekend I may well pick up a WiDi adapter.

I just really want to play HOI4 on a screen I don't need to squint at 🤣

smuggler.ie

How are you attempting to cast?

If TV (and laptop) have miracast support, it should allow to cast from within windows settings.

For chromecast you'd need to cast from chrome browser

banie01

You may have just hit the nail squarely on the head there re: MiraCast. I will take a trawl through the manual and settings for the TV later.

I have been trying to connect to the Philips via laptop display settings rather than hitting the cast button in chrome.

smuggler.ie

To see if laptop support miracast:

go RUN->dxdiag.exe->"save all information" report->read that txt report - there will be entry for Miracast, if its supported or not

On TV its either documentation or within menu, different TV brands call it differently. Dont know about philips, samsung call it "allshare"

Usually its ON by default and no way to turn off. If not discovered by Win - likely not present on TV

banie01

https://www.boards.ie/discussion/comment/120344458#Comment_120344458

Its a miracast issue. The TV doesn't support it, laptop does. I've just confirmed tho that casting from within chrome to the TV works. A partial result at least. Thanks a million for your help in troubleshooting this for me. Today I've learned there is a huge difference between Chromecast and Miracast when it comes to how a screen is cast.

I think I have a miracast dongle somewhere about the house, and if I don't? I'll pick one up.

smuggler.ie

Read about chromecast vs miracast

Miracast over Ethernet https://learn.microsoft.com/en-us/surface-hub/miracast-over-infrastructure

You might need WiFi as TV/dongle might not fill all requirement, but worth a shot

10-10-20

https://www.boards.ie/discussion/comment/120344458#Comment_120344458

Well done!