wireless packet flow explanation

[ammahend]

Hi My requirement is very simple , I will appreciate if someone can explain me the following concept as per the diagram mentioned below

I have 2 APs AP1 and AP2, both connect to switch on port f0/1 and f0/2 , the switch f0/3 inturn connects to a router on f0/0 , router's interface f0/1 connects to another switch which is wired network with ip add 192.168.2.0/24 .

1. APs broadcast 3 ssid (management , guest , cisco) respectively , how would the data flow happen for user connected to SSID cisco when pings another user connected to SSID guest , and how would data flow happen when user in SSID cisco ping a user 192.168.1.100 some user is wired network.

you can assume both the APs are autonomous and there is no controller.

I am looking for explanation in terms of frame tagging and packet encapsulation and depacsulation at various stages.

you can assume the IP nd vlan number on wireless network as you like.

2.if you are not tired yet then one mroe question with same topology , but this time the APs are lightweight and the controller is in a different subnet 192.168.1.0 , assume that the AP is already registered with controller , now how would the same above communication happen ,

I am looking for explanation in terms of frame tagging and packet encapsulation and depacsulation at various stages.

you can assume the IP and vlan number on wireless network as you like.

If you can refer me some doc its fine with me , I already went through many documents and nuggets , I do have a clear picture.

Thank you

[Saravanan Lakshmanan]

1.

client to AP ===> 802.11 frame.

AP to client ===> 802.11 frame. At AP, received wired side ethernet frame removes the ethernet header with tag and encapsulates the IP packet using 802.11 header with right Bssid for that vlan.

AP ethernet to switch interface ===> Tag/UnTag Ethernet frame. At AP, received 802.11 frames removes the 802.11 mac header, the inner packet will be used to encapsulate using ethernet frame with Tag based on received Bssid.

ARP request - Broadcast packet sent by wireless client to AP as unicast. Once it decapsulates the 802.11 header, the inner IP packet hits the wire on that broadcast domain to reach upstream wired switch and wireless on same AP.

2.

AP to WLC ===> capwap/lwapp. 802.11 packets are encapsulated on L3 IP-UDP.

WLC to AP ===> capwap/lwapp.

All the client (802.11) packets are encapsulated in a LWAPP packet by the LAP and sent to the WLC. WLC descapsulates the LWAPP packet and acts based on the destination IP address in the 802.11 packet. If the destination is one of the wireless clients...

check:-

https://supportforums.cisco.com/message/3489064#3489064

https://supportforums.cisco.com/message/3717713#3717713