Cambium Wi-Fi Deployment Guide for Bonjour Services

vku200 · March 4, 2024, 12:16pm

Bonjour Gateway feature enables communication between Bonjour clients and services across VLANs on your LAN. By default, Bonjour operates within a single subnet; however, Bonjour Gateway eliminates this limitation by forwarding multicast DNS (mDNS) request from client to service VLANs as required.

The term “Bonjour Gateway Service” typically refers to a networking component or feature that facilitates the communication of Bonjour-enabled devices across different network segments or subnets.

In a typical network setup, Bonjour services are limited to a single broadcast domain or subnet, meaning that devices within the same local network can easily discover each other using Bonjour. However, when there are multiple subnets or VLANs (virtual LANs) in a network environment, Bonjour traffic doesn’t naturally traverse these boundaries due to the limitations of multicast traffic

A Bonjour Gateway Service acts as a bridge between these network segments, allowing Bonjour traffic to be forwarded and properly managed across different subnets. It achieves this by intercepting and retransmitting Bonjour service advertisements and requests, effectively extending Bonjour functionality beyond individual subnets.

Configuration:

Go to cnMaestro - Configuration – Wi-Fi Profiles – Services – Check the box for Enabling Bonjour Gateway.
Click on the “Add New” button to create a new Bonjour Gateway Rule.

Provide the Bonjour Gateway “Service Name” - Choose the “Protocol” from the Protocol drop-down menu - Enter the From VLAN ID where the Bonjour service device is connected and enter the To VLAN ID where the client device is connected – Click on the “Add” button to create the rule and Save.

From - To

Notes:
• The ‘From VLAN” refers to Bonjour services to forward Bonjour request packets.
• The “To VLAN” refers to clients which are connected and sending Bonjour request packets, along with forwarded discovery messages.
• If you want to specify multiple VLANs for one or more services, you must create multiple Bonjour Gateway rules.
• Ensure that mDNS packets are not blocked by any ACLs when deploying Bonjour services.
• Establish IP-level communication between Bonjour Services and Bonjour Clients.
• If Bonjour clients and Bonjour Services reside in the same L2 network, Bonjour services do not require additional configuration.
• Since Bonjour service is available over Eth1 port of the Access Point, an additional configuration option in cnMaestro is enabled to allow bonjour over the uplink. If the Bonjour Service is over a Mesh Link, L2GRE or L2TP tunnel, this additional configuration will allow the service discovery.

• In case if the Bonjour service is reachable over Ethernet-2 or Ethernet-3 port (for Multi-Port APs), AP will automatically forward the queries and responses over these ports if Bonjour service is enabled.

Example for Chromecast Configuration:

Chromecast devices enable users to stream (cast) content from their smartphones, tablets, laptops or desktop computers to a monitor/ television with an available HDMI port.

Chromecast service rule is not available from the cnMaestro AP Group Configuration UI. However, this can be configured by entering the below rules in the User Defined Overrides filed of the AP Group in cnMaestro.

!
bonjour-fw rules Google-Cast googlecast 20 30
bonjour-fw rules Google-Cast googlezone 20 30
!

Explaining the CLI Configuration:
• “Google-Cast”: Refers to the name of the Bonjour service being defined.
• The “googlecast” service is used with Apple and Android devices.
• The “googlezone” service is used with Google Chrome web browsers, including Windows systems.
• “20”: From VLAN - Denotes the VLAN where the Bonjour service is hosted, which in this case is VLAN 20.
• “30”: To VLAN - Specifies the VLANs to which the Bonjour service will be forwarded, indicating that Bonjour messages related to the Google Cast service will be forwarded to VLAN 30.

There are multiple Bonjour services that can be discovered using mDNS protocol. Here is a partial list of some common Bonjour services:

Application	Service	Description
AirPlay	raop	(Remote Audio Output Protocol)
AppleTV	airplay	(Apple TV)
AppleTV	appletv-v2	(Apple TV Home Sharing)
AppleTV	touch-able	(Apple TV Remote APP (iOS Devices))
iTunes	atc	(Apple Shared iTunes Library)
iTunes	home-sharing	(iTunes Home Sharing)
DigitalAudio	daap	(Digital Audio Access Protocol)
AirDroid	airdroid	(AirDroid App)
AirPrint	ipp	(Air Print)
Printer	universal	(Universal/Shared)
Printer	print	(Universal/Shared)
Printer	cups	(Universal/Shared)
Chromecast	googlecast	(Apple & Android Devices)
Chromecast	googlezone	(Chrome Web Browser)