With Split MAC , the 802.11 protocol functionality is divided between AP & WLC. Below diagram shows how Split MAC architecture works where AP & WLC have their dedicated responsibilities. General rule is all real-time tasks are handled by AP (such as Probe Response, Packet buffering, Fragmentation, Queuing) & non real-time tasks handled by WLC (Such as Association / Di-association, Classifying, 802.1x/EAP authentication, etc)
In Local MAC mode AP is doing all of the functions including the one done by WLC in Split MAC architecture.
Below diagram shows the CAPWAP State machine where you need to understand this in order to determine from where you should start troubleshoot if something is not working.
Following are the key states of this process & will see few of these in details in future posts.
1. Discovery Process (L2 Broadcast, L3 Broadcast,DHCP Option43, DNS,Priming, Static, OTAP)
2. Join Process (Primary/Secondary/Tertiary/Global Bacup WLC, Master Controller Flag, Least Load WLC)
3. Image Process
4. Config State
5. Run State
1. AP Registration
2. WLC Discovery via DHCP Option 43
3. WLC Discovery via DNS