I set up four RB912 and a central RB2011 (which is the default gateway, connected to the Internet)
On each router I setup a virtual AP in order to have two SSIDs per router WifiA and WifiB
I created two VLANs, Vlan10 and Vlan11 - on interface ether1 for the RB912, and on localbridge for RB2011
I created two bridges, BriA for (WifiA + Vlan10), and BriB for (WifiB + Vlan11)
I assigned an IP address to each bridge (localbridge for the RB2011 LAN, BriA and BriB)
Access to and through WifiA works great
With WifiB however access to and through doesn't work (no pinging whatsoever) between the RB912s or between the RB912s and the RB2011
After reviewing the various parameters I came across the bridge STP setting
On BriA, this was set to none, while on BriB and Localbridge it was set to RSTP
I consequently set BriB's STP setting to none and traffic began to flow unhindered.
I'm not sure how that setting came to be altered for BriA, but all seems to be well now
Any thoughts ?