Occasional Contributor II

Broadcast Multicast ( BCMC ) Bonjour Problem

We are a K-12. Our wired network is divided into two huge /16 subnets.  Secondary Blocks are 172.16.0.0 / 16 and Primary has 172.17.0.0 / 16.  Block = Building.

 
Secondary School is mainly in blocks 1, 2,3, (... 4 admin)
Primary School is located in blocks 5,6,7
 
Our present Aruba setup goes like:
 
SSID   / VLAN  / Broadcast Multicast (BCMC) on SSID Level
 
Guest SSID  / 172.20.0.0 / 16 / DROPPED
Student SSID  / 172.21.0.0 / 16  / ALLOWED
Staff SSID  / 172.22.0.0 /16   /  DROPPED
BYOD SSID  / 172.23.0.0 / 16 / DROPPED
 
So regardless of your location, whether you are in Block 1 or Block 6, if you are connected to Staff SSID, you will be GRE-tunneled into 172.22/16 range. So if Bonjour is on, Apple TVs in Primary Block can be seen by computers in the Secondary.
 
Secondary school has around 900 Macbook Pros and ~200 iOS devices. 
Primary school has  500 Macbook pros and ~500 iOS devices. 
Our concurrent client count max out at around 1,500. 
 
Most of Primary School is connected to Student SSID while Secondary is in Staff SSID (for both student and staff devices).
 
BCMC is ALLOWED in Student SSID and DROPPED for the rest. The moment we ALLOW BCMC in Staff  SSID, instantly our network will come crashing!  Ping time outs, server unreachable, error rates on our switches goes to the roofs! And this affects both wired and wireless clients. 
 
Basically for Secondary School, Bonjour is not readily available as their laptops are configured by default to connect to Staff SSID, they have to switch to Student SSID if they want to use Airplay or any other Bonjour services. 
 
Our APs are mixed of AP121, AP105 and AP61 (very few AP125 and AP135). Total inventory of around 140. 
 
Our core and distribution switches are CISCO. Besides storm control on the CISCO switches, is there a particular BCMC setting that we can tweak to help us with our present situation?Our core switches are 45xx and distribution switches are 29xx. 
 
Cheers,
Marlon