Using Airplay with Double-NAT

Question

Level 1

14 points

Using Airplay with Double-NAT

Hello,

I have two routers. Router 1 is the router with all my devices connected to it (iPhones, MacBooks, etc.), router two's WAN port is connected to router one's LAN port and has NAT enabled, so this is a double NAT environment. NAT MUST be enabled on both of these routers. I have airplay enabled speakers on router 2. Currently I have to switch wifi networks to router two if I want to airplay music to those speakers. Is it possible to airplay music to those airplay speakers (again, the speaker MUST be connected to router two, an both routers MUST have NAT enabled), even when my source device (iPhone, MacBook, etc.) is connected to router 1?

I tried opening all airplay ports (referring to this article: https://techsupport.cambridgeaudio.com/hc/en-us/articles/200535411-What-firewall -ports-need-to-be-open-to-use-AirPlay-) from router one to router two, and from router two to the airplay device, and still no results.

Any ideas?

Thanks!

null-OTHER, Airplay speakers

Posted on Dec 19, 2016 2:55 PM

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Answer 1

Dec 19, 2016 4:37 PM in response to spatel1

It won't work.

The devices behind router2 NAT are hidden from router1 devices. The NAT is doing exactly as it should.

Try using DMZ .. in router1 if available to the WAN IP of router2.. but it might still not work.

What routers are these?

both routers MUST have NAT enabled

Can you spell out why .. then we might be able to spell out alternatives..

eg NAT routing is particularly for your main router to the internet.. but is not necessary in your network where a more ordinary router can be used.. or for isolation you can use vlans instead.

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Answer 2

Tesserax

Level 10

148,453 points

Dec 21, 2016 11:39 AM in response to spatel1

In addition to LaPastenague's comments, the AirPlay IP protocol suite relies on Bonjour. In turn Bonjour relies on multicast DNS (mDNS) which is not normally routable. With a double NAT condition, AirPlay on one subnet cannot make it over to the other and another solution would have to be implemented, like a Bonjour Proxy.

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Answer 3

Dec 20, 2016 1:16 PM in response to Tesserax

That is going to make even using vlan more complicated.

http://blogs.cisco.com/getyourbuildon/network-wide-bonjour-how-would-you-support -bonjour-across-multiple-vlans

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Answer 4

spatel1 Author

Level 1

14 points

Dec 21, 2016 11:41 AM in response to LaPastenague

In my case router 1 is an Apple AirPort Extreme and router 2 is an Asus AC1900. The reason both routers need to be NAT enabled is fairly complicated. In short, it is for a home automation system where router 2 creates a subnet inside of home network for all automation devices to be, anyway both routers NEED NAT enabled.

Thanks for all your replies! I will try all of these and get back to you with my results.

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Answer 5

Dec 21, 2016 12:30 PM in response to spatel1

AC1900 asus is a really flexible router.. it has loads of options and it might be possible to do dual homing.. ie setup a secondary IP where you directly interconnect the routers.

In fact it might work better with the Asus and the AE swapped around..

At the moment the Asus is double NAT inside AE network.. but with the Asus.. you can setup two different subnets directly.. and then put the speakers on the same network as the AE.

Loads of stuff that is possible with decent equipment.

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