P2P Blocking Disabled on 8540 WLC (AireOS 8.10.171.0) - 2.4 and 5 Ghz

[ciscoprolin]

Dear All,

we have disabled P2P Blocking on one of our SSIDs to enable Peer to Peer communication for a programming project. Our professor who is managing the project told us the clients will only see each other if they are in the same RF band. That is 2.4 Ghz clients will see all other 2.4 Ghz clients but not 5 Ghz clients (of the same SSID) and vice versa. 
Does anyone have an idea why that is ? This certainly isn't by design, right ?

Cheers,
Thorsten

[Flavio Miranda]

This is not true. RF band does not prevent on client to "see" each other.  By "see" I am refering to ping or share services through the network.

The clients radio dont matter if 2.4 or 5.0 will be used to communicate with Access Point not between Clients. P2P means they will talking each other through the WLC not directly. 

[ammahend]

Ask your professor, if the wireless is configured in for central switching or local (flex connect switching) ?

if configured for flexconnect switching, then he might be right you may have understood it wrong.

For central switching clients supports P2P blocking for clients associated to different APs. However, in flexconnect solution it only works for clients connected to the same AP, and since every AP operates in a different channel, hence he meant 2 between 2 channels not necessarily 2 different frequency range (2.4Ghz and 5Ghz)

you can read more here.

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-8/FlexConnect_DG.html#pgfId-43785

hope this helps.

[Rich R]

I'm with @Flavio Miranda on this one - I can't see how channel or band will make any difference, regardless of whether it's centrally or locally switched.  Yes, central/local can affect the way blocking works but this is about blocking being disabled.

As Flavio said the RF channel/band is only relevant to the connection between the client and the AP.  The packets are switched between the clients by the WLC (central) or AP/switch (local).

The possible misunderstanding is if they are not using the controller at all (direct peer to peer WiFi like many printers and other such devices can use for direct client connection where the device becomes the "AP")- in which case the WLC settings are not even in the equation because they're not actually using the AP.

[ammahend]

May be I read it wrong, is it not true that with flexconnect, p2p blocking disable action will only be applicable to Clients connected on same AP ? 

[Rich R]

With p2p blocking DISABLED there is no p2p blocking so anything can talk to anything - no restrictions at all.

What you're talking about is relevant when p2p blocking is ENABLED (Drop) for flex local switching.

[ciscoprolin]

Hi guys thanks for your feedback.
We're talking about a centrally switched WLC solution (with all APs in mode "local"). The professor told me that's what he has observed - that Android Clients connected to the same SSID (on same controller) are not able to see each other when connected via different RF bands. To me this looks like a bug and I'm gonna contact Cisco TAC.

best
Thorsten