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Hello all,

I am new to this forum and I have a question regarding the frame size for 802.11.

If I understand it correctly 802.11 allow frame sizes up to 2347 bytes, where ordinary Ethernet limits the frame size to 1518 (or 1522 with Q-tag).

My question is if I have a wireless computer that is associated with an Access Point, which is attached to an ordinary ethernet switch, what will happen if the wireless computer tries to send any frame larger than 1518 bytes into the switched network?

If the wired device L2 device (in your case the ethernet switch) doesn't support jumbo frames, then those frames will be dropped.

Most gigabit devices have support for jumbo frames. Jumbo frames usually max out at 9000 bytes.

Like Cisco's LWAPP can sense if the connection from the AP to the WLC has support for jumbo frames or not, if no, then it will use the MTU of the ethernet, which is 1500 bytes.

But I'm not sure what would happen if a packet bigger than 1500 bytes is directly sent to a L3 device, I think the L3 device might be able to fragment the packet into a smaller size.

Can some expert please clear this point.

Thanks

Vivek