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Is LSS Filtering process affected by RF Grouping?

I will put a diagram tomorrow but the basic idea is the following:

 

Controller A ---> AP Group A ---> AP 1 ----> IPAD (requesting Airplay - Apple TV Service)

Controller A ----> AP Group A ---> AP 2 ---> Airprint

Controller B ----> AP Group B ----> AP 3 ---> Apple TV. Configured on this Controller B, I have the same AP Group A but is not doing anything, I mean nothing is connected to the SSID's linked to that AP Group.

 

AP 1 is physically closed to AP 2 and 3.

My question is:

"Why APPLE TV  (AP 3) on a different WLC/AP Group/Subnet can be seen by IPAD?

My analysis is the following:

Based on my understanding the AP 1 send a message to any AP around him (in this case AP 2 and AP 3) using the higher signal power available but with the minimum bandwidth consumption in order to identify its neighbors and this information is registered into the WLC-A RRM DB. So when IPAD request Apple TV Services, Controller A would check on its RRM DB any AP neighbor to AP 1 (in this case AP 2 and 3) to create a AP Neighboring List. After doing that, WLC-A filters the SP/Service based on the AP 1 Neighboring list previously obtained along with service requested by IPAD so in this case, the WLC-A presents to the IPAD only the Apple TV service provided by AP 3 which is located a different WLC.

But, How is that possible?????. Is this situation caused by RF grouping or by having same AP Group on both WLC's so the mDNS services are broadcasted between them?

 

Any clarification is welcomed because I am not clear about this.

thanks

AC

 

 

 

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Hall of Fame Super Silver

Multiple controllers don't

Multiple controllers don't share mDNS information is what you need to understand.  Also you will have multiple mDNS entries if mDNS snooping is enabled.  You have to also look at what really the bonjour gateway is used for as it may not work in your situation.  Filtering per WLAN on a single WLC would work, but multiple WLC, might not.

Scott

-Scott
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Hall of Fame Super Silver

RF Groups is defined when you

RF Groups is defined when you have AP's that can hear each other in an area.  That being said, in a building, for example, you would only have one RF Group defined and one Mobility Group Defined.  LSS works this way.... If a bonjour device is associated to an access point, that device bonjour services will only be seen by other devices on that given access point or the adjacent neighbor access point.  Basically two hops.  This is how this works... Your setup is not like many wireless setups out there.  The use of AP Groups is fine, but your mDNS profile is based out of your WLAN.  So depending on your what your mDNS services you want to be allowed, then you need to define that on the WLAN.  If AP3 is close to AP1, then they are neighbors and you would see the same results if you had LSS disabled.  This whole bonjour is to really help bridge the gap between Apple and enterprise per say.  To allow for bonjour to cross layer 3 boundaries.  If devices are all on the same layer 2, well... that is how bonjour works and all devices will be seen.

Scott

-Scott
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Thank you so much Scott for

Thank you so much Scott for your note.

 

Looks like the WLC-A and WLC-B has the same mDNS SP DB so the traffic can be sent from  AP-1/WLC-A/IPAD to the AP-3/WLC-B/AppleTV.

 

Do you see any misunderstanding on the explanation that I put on this post at the beginning?

I am doing another tests and I will post my results before closing this post.

 

regards

 

 

 

Hall of Fame Super Silver

Multiple controllers don't

Multiple controllers don't share mDNS information is what you need to understand.  Also you will have multiple mDNS entries if mDNS snooping is enabled.  You have to also look at what really the bonjour gateway is used for as it may not work in your situation.  Filtering per WLAN on a single WLC would work, but multiple WLC, might not.

Scott

-Scott
*** Please rate helpful posts ***

SP DB which is basically mDNS

SP DB which is basically mDNS entries has multiple records as you mention because mDNS snooping is enabled.

 

On the other hand, I am just verifying that mDNS information is local to the WLC based on the tests I am running. Sometimes the theory/documentation from Cisco does not match the results that you get from your own testing process.

Thanks for your reply. I finished my testing.

As you said, the RRM DB information that is matched with the SP DB (mDNS entries) in order to provide to the IPAD with the Apple TV Services required is local to each WLC. I repeated the test and AP-1 on WLC-A can see the neighbour on AP-3 which is connected to WLC-B but the SP DB on WLC-A only shows mDNS entries for Apple TV devices connected directly to the AP's on that WLC-A so no mDNS data is traversing between controllers.

Even though they are not correlated, I just wanted to check if my situation had something to do with the following link:

https://supportforums.cisco.com/discussion/11899486/wlc-75-bonjourmdns-multiple-sites

 

 

Something interesting that I

Something interesting that I found on the command;

 

SHOW AP AUTO-RF 802.11a/b CISCO-AP (applied on WLC-3) which I assume is being used to build the RRM DB for neighbor AP's is not showing the correct WLC (WLC-5) for the neighbor AP-3.

Do you know if the AP MAC Entry below which is linked to a different controller is used by LSS filtering process, so this entry is ignored (because is an external WLC) at the time of selecting SP Services available for the local WLC?

Nearby APs
    AP 00:23:eb:e6:26:40 slot 1..................  -76 dBm on  64 (172.23.111.22)

 

I also found that the

I also found that the following command shows you the neighbouring AP, so I am assuming this information feeds the RRM DB of the WLC to which the AP is connected. (Part of the show command output was omitted)

(Cisco Controller) >show ap auto-rf 802.11a Scar-Ctr-L2-AP2602-214

Number Of Slots.................................. 2
AP Name.......................................... Scar-Ctr-L2-AP2602-214
MAC Address...................................... 88:5a:92:a7:5f:20
  Slot ID........................................ 1
  Radio Type..................................... RADIO_TYPE_80211a
  Client Signal To Noise Ratios
    SNR    0 dB.................................. 0 clients
    SNR    5 dB.................................. 0 clients
  Nearby APs
    AP 00:23:eb:e6:26:40 slot 1..................  -76 dBm on  64 (172.23.111.22)
    AP e8:04:62:0a:fd:60 slot 1..................  -64 dBm on 149 (172.23.111.22)

  Radar Information
  Channel Assignment Information
    Current Channel Average Energy...............  -84 dBm

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