Multiple VLANs on one SSID: how does this actually work?

[gglynn]

I'm familiar with the procedure for bridging multiple VLANs between two Aironet bridges (e.g. 1300 series) over a single SSID, but I have no idea how it works, and that really bugs me.

Since frame tagging a la 802.1q isn't part of the WiFi protocols (at least I don't think it is), how do the bridges differentiate traffic in the 802.11 packets? Is there some Cisco-proprietary extension of the standards to support 802.1q tags in the 802.11 headers? Or is it something else?

[scottmac]

The thing that makes the bridging proprietary is not the frame or headers, it's (usually) the timing.

If you really have to see it with your own eyeballs, load up a copy of WireShark (www.wireshark.org)with WinPcap (http://www.mirrorservice.org/sites/ftp.wiretapped.net/pub/security/packet-capture/winpcap)

- both are free - and capture a stream; you'll see every byte of detail for all levels communicated.

And, for future reference, nobody here gets paid to answer your questions; if you get snippy and start demanding, I can pretty much guarantee crickets back atcha.

Your question was answered.

"Have a nice day"

Scott

[Rob Huffman]

Hi Bill,

I just realised that I didn't also rate your great work with trying to explain this. 5 points for going the extra mile here :)

Take care,

Rob

[gglynn]

He didn't answer the question, though. Can someone else answer the question I actually asked? Here it is again, reworked slightly to make it clearer:

Since VLAN tagging a la 802.1q isn't part of the WiFi protocols, how do Aironet 1300 series bridges differentiate traffic from different VLANs (tagged by 802.1q on the wire) when they're bridged over a single SSID? Is there some Cisco-proprietary extension of the standards to support 802.1q tags in the 802.11 headers, or are the 802.1q packets encapsulated completely within 802.11 packets, perhaps?