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mDNS reflector

The mDNS reflector allows devices on different networks and VLANs to discover supported network services, such as Apple AirPlay and Google Chromecast, using multicast DNS (mDNS) and DNS Service Discovery (DNS-SD).

In segmented environments, devices typically can't discover Bonjour services (Apple's zero-configuration networking services) outside their local subnet or VLAN. mDNS reflector forwards mDNS advertisements and discovery requests between selected interfaces while maintaining network segmentation.

mDNS is available only on internal network interfaces. WAN and VPN interfaces aren't supported because mDNS traffic isn't routed beyond the internal network segments.

mDNS reflector doesn't automatically allow application traffic. Make sure that the necessary firewall rules are configured to allow traffic between the participating networks for the required services.

Existing mDNS reflector configuration is retained when you turn off mDNS reflector. When you turn it on again, the firewall restores the previous configuration.

Example

Discovering an AirPlay device doesn't automatically allow AirPlay communication. You must configure the necessary firewall rules to allow traffic between the client and the service provider.

High availability

mDNS reflector supports high availability (HA) deployments.

In HA deployments, mDNS reflector behaves as follows:

  • The configuration is synchronized between HA devices.
  • mDNS service discovery remains available during failover events.