In addition to allowing the software to communicate through any security barriers in place (such as antivirus or firewalls), the network must also be capable of using the correct communication protocols required for the automatic discovery of your mirroring device. Included below is an overview of all networking requirements needed to use Bonjour services such as AirPlay properly.
Local traffic only:
AirPlay applications use a direct connection method through the local network. Reflector directly connects iOS devices, Chromebooks, Android devices, AirPlay Mac computers, and AirParrot equipped computers.
You must be on the same VLAN or subnet within the network to connect; Apple's AirPlay cannot cross subnets/VLANs natively, this is a limitation of Apple's AirPlay. If you require the connecting devices to be on different subnets, then you may wish to have the IT department look into a Bonjour Gateway for the network. Some network hardware will have this functionality built-in and others may require a third-party solution.
The Bonjour Gateway will allow AirPlay to cross subnets/VLANs so your devices may communicate. This, however, will show all AirPlay devices on the network, so the users may wish to change the broadcast name and add an AirPlay password as well.
Aerohive is one such developer for a Bonjour Gateway. Many large users have added this to their network and can mirror across subnets/VLANs.
The local network must be allowed to run Bonjour, mDNS, and Multicast must be enabled. The Bonjour protocol consists of service announcements and service queries that allow devices to ask for and advertise specific applications, such as file or printer sharing and AirPlay. For our purposes, we are primarily concerned with AirPlay availability.
Each query or advertisement is sent to the Bonjour multicast address for delivery to all clients on the subnet. Apple’s Bonjour protocol relies on Multicast DNS (mDNS) operating at UDP port 5353 and sends to these reserved group addresses:
IPv4 Group Address - 184.108.40.206 IPv6 Group Address - FF02::FB
The addresses used by the Bonjour protocol are link-local multicast addresses and thus are only forwarded locally. Routers cannot use multicast routing to redirect the traffic because the time to live (TTL) is set to one, and link-local multicast is meant to stay local by design.
AirPlay ports must be available on the subnet or VLAN being used to connect your devices as well. Here is the port list that AirPlay will use with our applications:
220.127.116.11 > tcp > port - 5353 (MDNS - Apple) (These ports are used for AirPlay detection on the network)
18.104.22.168 > udp > port - 5353
udp > port 1900 (Google Cast detection)
tcp > port - 7001 (seen with video)
tcp > port - 7000 (seen with picture/file)
tcp > port - 7100 (seen with display-mirroring)
udp > port - 7010 (seen with display-mirroring)
udp > port - 7011 (seen with display-mirroring) tcp>port-47000 (Audio connection negotiation)
tcp > port - 49152-65535 (dynamic ports) (Audio connection) udp > port - 49152-65535 (dynamic ports) (Audio connection) tcp > port 8008 (Google Cast)
tcp > port 8009 (Google Cast)
Reflector will also access TCP 80 for any directly connected videos (such as YouTube), and that should be the only external access the application uses. Everything else will be local traffic with no need to access the internet.
Some networks may use a Multicast group to manage multicast traffic. When multicast is enabled, then all multicast traffic will flow to all connected clients in a subnet. Using a multicast group to limit the number of clients receiving the multicast data reduces the overall workload being placed on the network.
Using groups is typically not required, but it can help many AirPlay devices on the network. When creating multicast groups, there are 3 important factors to consider:
- Multicast groups must include the subnets or VLANs where AirPlay devices (and clients that may mirror those devices) are connected.
- All AirPlay devices and clients must be members of the multicast group.
- If using multicast groups, then IGMP Snooping must be enabled on your network to allow your devices to listen to the multicast group. This allows your devices to see the multicast group traffic without affecting the rest of your network.
Using all of the above information contained in this guide, you should ensure that any network is compatible with AirPlay and Bonjour services. For answers to any specific questions or more advanced configuration details, please email us at email@example.com or contact your network hardware manufacturer.