How can you tell from a 440x controller what members are configured in your RF groups (or sub-groups)?
Also, the good RRM doco
Mentions that packets are sent to the controller from the APs. Do this packets get encapsulated in LWAPP ?
I think I heard somewhere that they are udp port 12214 for 802.11b/g and udp 12215 for 802.11a packets that get sent to the WLC?
Can anyone confirm these two points please?
Hi Ken and Bruce,
These are 802.11 frames and I found them with a destination address of 01:0B:85:00:00:00. See the attached file.
Notice the first and third frames are from the same source and are 60 seconds apart (the default interval).
Ken is correct, lowest rate, highest power and this is done on every channel.
The data contains:
Group ID (RF group name)
WLC IP Address
Neighbor Message Channel
This is all verified using a hash based on the RF Group Name. So, if the message is undecipherable, the RF Group Name must be different.
Hope this helps.
Edit: you may wonder why we don't hear the source of the second packet 60 seconds later. Well, it was at 12% signal, so I'm guessing we just didn't hear it at the next interval.
Edit2: FYI Ken, it has been raining here non-stop for 2 weeks. You're not missing much at the moment!
Matt should be able to confirm this for us, but I believe these are a special form of "AP Beacon," which, other than obeying the rules of the 802.11 road (CSMA/CA) can only be decoded by the APs themselves and not the clients.
That being said, there is a downside to this. These "beacons," though infrequent, are sent at the highest tranmsit power and lowest data rate, regardless of the controllers configuration (i.e. 100mW and 1.0Mbps for the 802.11b radio).
Matt, are there any protocol decodes for these beacons?
From Appedix B of the deploment guide for all protocols and ports (http://www.cisco.com/en/US/customer/docs/wireless/technology/controller/deployment/guide/dep.html#wp1068265).
All messages are carried in UDP datagrams. For all 802.11b/g RRM messages, the UDP datagrams use UDP ports 12124 (client) and 12134 (manager). For all 802.11a RRM messages, the UDP datagrams use UDP ports 12125 (client) and 12135 (manager). UDP ports 12124, 12134, and 12135 must be allowed between all WLCs belonging to an RF Group.
FYI this is for communication between members of an RF group (WLCs). The traffic from AP to WLC is LWAPP control on 12223.
RF Group members are displayed under Wireless>802.11b/g/n or 802.11a/n>RRM>RF Grouping.