The Apple Bonjour protocol is a zero-configuration solution, which simplifies network configuration and enables communication
between connected devices, services, and applications. Using Bonjour, you can discover and use shared services with minimal
intervention and configuration. Bonjour is designed for single Layer-2 domains, which is ideal for small, flat, single-domain
setups, such as home networks. The Cisco Wide Area Bonjour solution eliminates the single Layer-2 domain constraint and expands
the scope to larger Layer-3 wired and wireless networks, as well as SD-Access networks.
The Cisco Wide Area Bonjour application is a software-defined controller-based solution that enables devices to advertise
and discover Bonjour services across Layer-2 domains, making it applicable to a wide variety of wired and wireless enterprise
networks. The Cisco Wide Area Bonjour application also addresses problems relating to security, policy enforcement and service
administration on a larger scale. The distributed architecture is designed to build isolated flood boundaries and policy enforcement
points, and to enable management of services. With the Cisco Wide Area Bonjour application, you can introduce new services
into your existing environment, without modifying the existing network design or configuration.
The intuitive GUI provides you with centralized access control and monitoring capabilities, combined with the scalability
and performance required for large-scale Bonjour services deployments.
The Cisco Wide Area Bonjour application operates across two integrated domain networks.
Local-Area SDG Domain: The Cisco Catalyst switches at Layer 3 boundary function as Service Discovery Gateway (SDG) for local cache discovery and
distribution functions between local VLANs. In this controller-less Bonjour solution, the SDG gateway switch provides a single
gateway solution at the LAN and Wireless Distribution block. The SDG switch communicates with local Bonjour endpoints to build
and manages the services information. The Bonjour gateway function is ineffective between Bonjour endpoints in same Layer
2 network, as they follow standards-based flood-and-learn rule.
Wide-Area SDG Domain: The Wide Area Bonjour domain is a Controller-based solution. The Bonjour gateway role and responsibilities of Cisco Catalyst
switching is extended from the SDG to an SDG-Agent. The network-wide distributed SDG-Agent devices establish a lightweight,
stateful and reliable communication channel with centralized Cisco DNA-Center Controller running the Wide Area Bonjour application.
The service routing between the SDG Agents and the Controller operates over regular IP networks using reliable TCP port 9991
between the Cisco DNA Center and the SDG Agent devices. The SDG Agents route locally discovered services based on the export
Cisco Service Discovery Gateway (SDG) and Wide Area Bonjour gateway function is supported on Cisco Catalyst Switch and Cisco
ISR 4000 series routers. See Solution Components for the complete list of supporting platforms, software versions and license levels.
Cisco IOS supports classic and new method of building local Bonjour configuration policies. The classic method is based on
service-list mdns-sd CLI whereas the new method is based on mdns-sd gateway. We recommend using the new mdns-sd gateway method since the classic configuration support will be deprecated in near future releases.
The classic to new method CLI migration is manual procedure to convert the configuration.
The Bonjour service policies on Cisco SDG Gateways are effective between local VLANs. In addition to these, a specific egress
policy controls the type of services to be exported to the controller. The Layer 2 Multicast-DNS Bonjour communication between
two end-points on same broadcast domain is transparent to gateway.
To enable end-to-end Wide Area Bonjour solution on Wireless networks, the Cisco WLC controller must not enable mDNS Snooping
function. The upstream IP gateway on the dedicated Cisco Catalyst switch must have the Bonjour gateway function enabled for
Cisco Wireless LAN Controller must enable AP Multicast with unique Multicast group. Without AP joining WLC Multicast group
the mDNS messages will not be processed between client and gateway switch. Multicast on Client SSID or VLAN is optional for
other multicast applications and not mandatory or required for Bonjour solution.
Cisco Catalyst 9800 WLC can be configured as mDNS Gateway. In this mode, the Cisco Catalyst 9800 WLC supports Local-Area Bonjour
gateway solution limited to Wireless only networks. Cisco Catalyst 9800 does not support Wide Area Bonjour. For end-to-end
Wired and Wireless Bonjour support, we recommend using upstream Cisco Catalyst Switch as IP and Bonjour gateway.
The Cisco DNA Service for Bonjour solution is an end-to-end solution that includes the following key components:
Cisco SDG Agent: The Cisco Catalyst Switch or an ISR 4000 series router functions as a Service Discovery Gateway (SDG) Agent and communicates
with the Bonjour Service endpoints within the Layer 2 domain and central Cisco DNA Center controller.
Cisco DNA Controller: The Cisco DNA Controller provides a secure channel with trusted SDG Agents, for centralized services management and controlled
Cisco Wireless LAN Controller: The Cisco Wireless LAN Controller (WLC) transparently switches mDNS messages between wireless clients and upstream Bonjour
gateway switch in distribution layer network.
Endpoints: A Bonjour endpoint is any device that advertises or queries Bonjour services conforming to RFC 6762. The Bonjour endpoints
can be in either LAN or WLANs. The Wide Area Bonjour application is designed to integrate with RFC 6762 compliant Bonjour
services, including Apple, Microsoft, Google, HP and more.
Cisco Wide Area Bonjour Service Workflow
The Cisco Wide Area Bonjour solution follows a client-server model. The SDG Agent functions as a client and the Cisco Wide
Area Bonjour application Cisco DNA Center functions as a server.
The following sections describe the workflow of service announcement and discovery in the IP network.
Announcing Services to the Network
The endpoint devices (Source) in the Local Area Bonjour domain send service announcements to the SDG Agent and specify what
services they offer. For example, _airplay._tcp.local, _raop._tcp.local, _ipp._tcp.local, and so on.
The SDG Agent listens to these announcements and matches them against the configured Local Area SDG Agent policies. If the
announcement matches the configured policies, the SDG Agent accepts the service announcement and routes the service to the
Discovering Services Available in the Network
The endpoint device (Receiver) connected to the Local Area SDG Agent sends a Bonjour query to discover the services available,
using the mDNS protocol.
If the query conforms to configured policies, SDG Agent responds with the services obtained from appropriate service routing
via the Wide Area Bonjour Controller.
Wide Area Bonjour Multi-Tier Policies
The various policies that can be used to control the Bonjour announcements and queries are classified as the following:
Local Area SDG Agent Filters: Enforced on the SDG Agent in Layer-2 Network Domain. These bi-directional policies control the Bonjour announcements or
queries between the SDG Agents and the Bonjour endpoints.
Wide Area SDG Agent Filters: Enforced on the SDG Agent for export control to the Controller. This egress unidirectional policy controls the service routing
from the SDG Agent to the controller.
Cisco Wide Area Bonjour Policy: Enforced on Controller for global service discovery and distribution. Policy enforcement, between the controller and the
IP network is bi-directional.
The following table lists the supported controller, along with its hardware and software version.
Cisco DNA Center Appliance
Cisco Wide Area Bonjour Application
Cisco DNA Center Appliance
The following table lists the Supported SDG Agents along with their licenses and software requirements.
Supported SDG Agent
Local Area SDG
Wide Area SDG
Cisco Catalyst 9200 Series Switches
Cisco Catalyst 9200L Series Switches
Cisco Catalyst 9300 Series Switches
Cisco Catalyst 9400 Series Switches
Cisco Catalyst 9500 Series Switches
Cisco Catalyst 9500 Series Switches - High Performance
Cisco Catalyst 9600 Series Switches
Cisco Catalyst 9800 Series Wireless Controllers
Cisco 5500 Series Wireless Controllers
Cisco 8540 Wireless Controller
Cisco Catalyst 6800 Series Switches
IP Services + DNA-Addon
Cisco Catalyst 4500-E Series Switches
IP Services + DNA-Addon
Cisco Catalyst 4500-X Series Switches
IP Services + DNA-Addon
Cisco Catalyst 3650 Series Switches
Cisco Catalyst 3850 Series Switches
Cisco Catalyst 2960-X Series Switches
Cisco Catalyst 2960-XR Series Switches
Cisco 4000 Series Integrated Services Routers (ISR)
Cisco Wide Area Bonjour Supported Network Design
Traditional Wired and Wireless Networks
The Cisco DNA Service for Bonjour supports various LAN network designs commonly deployed in the enterprise. The SDG Agent
providing Bonjour gateway functions is typically an IP gateway for wired end-points that could be residing in the distribution
layer in multilayer network designs, or in the access layer in routed access network designs.
The following figure shows various topologies which are explained further in the section.
Multilayer LAN: In this deployment mode, the Layer 2 Access switch provides the transparent bridging function of Bonjour services to Distribution-layer
systems that act as the IP gateway and SDG Agent. There is no additional configurration or new requirement to modify the existing
Layer-2 trunk settings between the Access and Distribution Layer Cisco Catalyst Switches.
Routed Access: In this deployment mode, the first-hop switch is an IP gateway boundary and therefore, it must be combined with the SDG
The Cisco DNA Service for Bonjour also supports various Wireless LAN network designs commonly deployed in the Enterprise.
The SDG Agent provides consistent Bonjour gateway functions for the wireless endpoints as in wired networks. In general, the
IP gateway of the wireless clients is also a Bonjour gateway. However, the placement of the SDG Agent may vary depending on
the Wireless LAN deployment mode.
Cisco SD Access Wired and Wireless Networks
In Cisco SD-Access network, the Fabric Edge switch is configured as the SDG Agent for fabric-enabled wired and wireless networks.
Wide Area Bonjour policies need to be aligned with the SD-Access network policies with respect to Virtual Networks and SGT
policies, if any.
Wide Area Bonjour uses two logical components in a network:
SDG Agent: The Fabric Edge switch is configured as the SDG Agent, and the configuration is added only after the SD-Access
Wide Area Bonjour Controller: The Wide Area Bonjour application in the Cisco DNA Center acts as the Controller.
The Wide Area Bonjour communication between the SDG Agent and the Controller takes place through the network underlay. The
SDG Agent forwards the endpoint announcements or queries to the Controller through the fabric underlay. After discovering
a service, a Bonjour-enabled application establishes direct unicast communication with the discovered device through the fabric
overlay. This communication is subject to any configured routing and SDG policies.
Local and Wide Area Bonjour Policies
The Cisco Wide Area Bonjour policy is divided into four unique function to enable policy based Bonjour services discovery
and distribution in two-tier domains. The network administrator must identify the list of Bonjour services that needs to be
enabled and set the discovery boundary that can be limited to local or global based on requirements. Figure below illustrates
enforcement point and direction of all four types of Bonjour policies at the SDG Agent level and in Cisco DNA-Center Wide
Area Bonjour application:
Local Area Bonjour Policy
The Cisco IOS Bonjour policy structure is greatly simplified and scalable with the new configuration mode. The services can
be enabled with intuitive user-friendly service-type instead individual mDNS PoinTeR (PTR) records types, for example select
AirPlay that automatically enables video and audio service support from Apple TV or equivalent capable devices. Several common
types of services in Enterprise can be enabled with built-in service-types. If built-in service type is limited, network administrator
can create custom service-type and enable the service distribution in the network.
The policy configuration for the Local Area Bonjour domain is mandatory, and is a three step process. Figure below illustrates
the step-by-step procedure to build the Local-Area Bonjour policy, and apply to enable the gateway function on selected local
To configure local area bonjour policies, enable mDNS globally. For the device to receive mDNS packets on the interface, configure
mDNS gateway on the interface. Create a service-list by using filter options within it allow services into or out of a device
or interface. After enabling mDNS gateway globally and on the interface, you can apply filters (IN-bound filtering or OUT-bound
filtering) on service discovery information by using service-policy commands.
Built-In Service List
The Cisco IOS software includes built-in list of services that may consist of one more Bonjour service-type. A single service-list
may contain more than one service-type entries with default rule to accept service announcement from service-provider and
the service query request from receiver end-points. If selected service-type contains more than one Bonjour service-types
(PTR), then a service announcement or a service query is honoured when the announcement/query is for any one of these included
Bonjour service-types. For example, Apple Time Capsule Data service-type consists of both_adisk and _afpovertcp built-in PTRs,
however if any end-point announces or requests for only _afpovertcp service, then SDG Agent will successfully classify and
process the announcement or request. The service-list contains implicit-deny for all un-defined built-in or custom services
Table below illustrates complete list of built-in Bonjour services that can be used to create policies in local area Bonjour.
Table 1. Cisco IOS Built-In Bonjour Service Database
AirServer Mirroring Service
Amazon Fire TV
Apple TV 2
Apple File Share
Apple iTunes Library
Apple iTunes Music
Apple iTunes Photo
Apple KeyNote Remote Control
Apple Remote Desktop
Apple Remote Event
Apple Remote Login
Apple Screen Share
Apple Time Capsule Data
Apple Time Capsule Management
Apple MS Window File Share
Apple iTunes Data Sync
Phillips Hue Lights
Printer – Internet Printing Protocol
Printer – IPP over SSL
Linux Printer – Line Printer Daemon
Roku Media Player
Spotify Music Service
Custom Service List
The Custom service list allows network administrator to configure service if built-in Bonjour database does not support specific
service or bundled service types. For example, the file-sharing requirement demands to support Apple Filing Protocol (AFP)
between macOS users and Server Message Block (SMB) file transfer capability between macOS and Microsoft Windows devices. For
such requirements the network administrator can create an custom service list combining AFP (_afpovertcp._tcp.local) and SMB
The Service-List provides flexibility to network administrator to combine built-in and custom service definition under single
list. There is no restriction on numbers of custom service definitions list and association to single service-list.
The Local Area Bonjour policy in Cisco IOS provides flexibility to network administrator to construct service policies that
can align service announcement and query management in same or different local networks. The service-policies can be tied
to either ingress or egress direction to enforce service control in both directions. The following sub-sections provide more
details on service policy configuration.
Ingress Service Policy
The ingress service policy is a mandatory configuration element that is used to permit the processing of incoming mDNS service
announcement and query requests. Without ingress service policy, the Bonjour gateway function on a targeted Wired or Wireless
network is not enabled. The ingress service policy provides flexibility to permit service announcement and query on each user-defined
service-types, i.e. permit accepting AirPlay service announcement and query request, but enable Printer service query request
Egress Service Policy
The egress service policy is an optional configuration and not required in following two conditions:
The egress service policy is not applicable in local VLAN where the expected Bonjour end-points are service-provider only,
i.e. Service-VLAN network may contain only IT managed service-provider end-points such as Apple TV, Printers etc. as these
end-points do not query for other service-types in the network.
The Wired or Wireless users must receive services only from Wide Area Bonjour domain by Cisco DNA-Center, and not from other
Bonjour end points connected to the same SDG Agent.. The egress service policy configuration is only required when an SDG-Agent
must distribute locally discovered Bonjour services information from one VLAN to other. For example, based on ingress service
policy the SDG-Agent discovered and cache the AirPrint capable Printer from VLAN-A, if the receiver endpoint in VLAN-B wants
to discover Printer information from VLAN-A then the SDG-Agent must have ingress and egress service policy permitting AirPrint
service on both VLANs.
Conditional Egress Service Policy
The network administrator can optionally customize the egress service policy to enable conditional service response from sourced
from specific VLAN network. For example, based on ingress service policy the SDG-Agent may discover AirPrint capable Printers
from VLAN-A and VLAN-C networks. With conditional Local Area Bonjour egress service policy rule, the network administrator
may limit distributing Printer information discovered from VLAN-A to the receivers in VLAN-B network and automatically filters
VLAN-C Printers. The conditional egress service policy support is optional setting and only applicable on out direction service
Service Status Timer Management
The Bonjour service-provider end-points may announces one or more services in the network combining mDNS records and time-to-live
(TTL) service timers for each record. The TTL value provides assurance of end-point availability and serviceability in the
network. The SDG Agents ensures that it contains up to date information in its local and updates global services in Controller
based on TTL and other events in Local Area Bonjour domain. The network administrator must configure the service status timer
where service-provider endpoint discovery is permitted.
Wide Area Bonjour Policy
The SDG-Agent mandatorily requires the controller bound Wide Area Bonjour service export policy to control routing local services
and discover remote services from Cisco DNA-Center. As the Cisco DNACenter and SDG-Agent builds trusted communication channel
the remote service response from Wide Area Bonjour App is implicitly permitted at SDG-Agent. Hence the Wide Area Bonjour policy
is unidirectional it only requires egress service policy towards controller.
The Wide Area Bonjour policy hierarchy and structure is identical as described in Local Area Bonjour Policy structure section.
Following sub-section provides step-by-step reference configuration to build and enforce the policy to enable the successful
communication with Wide Area Bonjour App in Cisco DNA-Center.
Service List – Built-In and Custom
The network administrator must create new controller bound egress service list for the Wide Area Bonjour domain. In most common
network deployment model, the Wide Area Bonjour service list may contain same service-types as the Local Area Bonjour to implement
common services between both domains. Based on requirements, certain services can be limited to Local Area and prevent routed
in Wide Area Domain, then by default only allowed service list entries are permitted and rest are dropped with implicit deny
Ingress Policy Direction
The ingress service policy for Wide Area Bonjour domain is not required and cannot be associated to the controller.
Egress Policy Direction
As described the Bonjour policy structure between Local Area and Wide Area is consistent, however the enforcement point is
different. We recommend configuring separate Service-List and Service-Policy for Wide Area Bonjour domain as it may help building
unique policy set for each domain.
Conditional Egress Service List
The Wide Area Bonjour egress service list configuration can be customized to conditionally route the service or query request
to the Cisco DNA-Center. With this alternative configuration settings, the network administrator can route the service or
query the request in Wide Area Bonjour domain from specific local source VLAN network instead globally from entire system.
Wide Area Bonjour Service Status Timer Management
The Cisco DNA-Center centralizes the services information from large scale distributed SDG-Agents across the network. To maintain
a scale and performance of controller the services routing information is transmitted and synchronized periodically by each
SDG-Agent network devices. To protect system and network performance the scheduler base service information exchange allows
graceful and reliable way to discover and distribute Bonjour services across Wide Area Bonjour domain.
In most large-scale network environment, the default Bonjour service timers on SDG-Agents are by default fine-tuned and may
not need any further adjustments. Cisco recommends retaining the interval timer values to default and adjust only based on
any user experience issue and consider modified parameters do not introduce scale and performance impact.