Controller Based WLANs

This feature enables the wired mDNS/SSDP devices which are not directly connected to controller or not trunked in the controller to be discovered through mDNS/SSDP messages.This may be a requirement in some installations where the mDNS/SSDP device is connected to a switch and is part of a VLAN which is not trunked in the controller.

There are currently 3 use-cases depends on the network topology for now.

Use-case#1

If AP uplink is an access port with access VLAN x, AP does mDNS aggregation for VLAN x.

Requirements

• VLAN needs to be created on controller using command “vlan x”
• Native VLAN ID needs to be configured in system profile as vlan x
• Enable multicast aggregation knob in ap-system profile

Use-case#2

If AP uplink is trunk port with native vlan as x (no uplink-vlan configured for AP), AP does mDNS aggregation for VLAN x.

Requirements

• VLAN needs to be created on controller using command “vlan x”
• Native VLAN ID needs to be configured in system profile as vlan x
• Enable multicast aggregation knob in ap-system profile

Use-case#3

If AP uplink is trunk port with native vlan as x, allowed vlans as x,y,z and ‘uplink-vlan’ configured as vlan y for AP. In this case AP does mdns aggregation for VLAN y

Requirements

• Uplink-vlan needs to be configured as vlan y in ap’s provisioning   parameters and reboot ap
• VLAN needs to be created on controller using command “vlan y”
• Native VLAN ID is configured in system profile as vlan x
• Enable multicast aggregation knob in ap-system profile

• Configuration Knob ap-multicast-aggregation is provided under ap system profile to configure and by default it is disabled.
• Tunnel 0x8000 shall be created between the Wireless Controller and the AP  if both ap-multicast-aggregation knob and Airgroup knob  is enabled. 
• The AP uplink vlan will be used for the tunnel if provisioned otherwise the Native Vlan shall be used.
• The AP work will be to collect mDNS packets from the wired devices which are part of the same VLAN and redirect it to the tunnel. It will also redirect the mDNS traffic from controller to the AP uplink.
• The Native VLAN or the Uplink VLAN whichever is used for the Split tunnel should be the same VLAN which the wired Airgroup device belongs.
• The VLAN in which the wired mDNS device terminates needs to be configured in the controller. No need to create an SVI for it or attach port to it.
• In case the Multicast AP aggregation knob is tuned ON from an OFF state then an mDNS/SSDP device discovery packet will sent for the VLAN in which the Split tunnel is created if the Airgroup knob is also ON

Network Diagram

Navigate to Configuration > Advanced Services > All Profiles, Under Profiles ,select AP>AP System> <Profile-Name> Under Basic >General, select the checkbox next to AP multicast aggregation  >Click Apply

Find below screenshot.

Recommended

• Ensure that this feature is turned on for a single AP per VLAN per controller.
• If the feature is enabled on two APs belonging  to same VLAN but terminating on different controllers, then these controllers should be part of the same AirGroup domain.

Verification

• Make sure airgroup feature is turned on along with this knob by command "show airgroup status"
• MDNS AP VLAN aggregation enabled from AP system profile.

Limitations

mDNS aggregation by AP feature is not supported on RAP,  Mesh APs and Remote Mesh Portal.