Wireless Mobility Problems?

[paul.l.kyte]

I have three Wireless LAN Controllers that are configured in the same Mobility Group. Two of the controllers have a the same WLAN (SSID) but the third doesn't. All three have other WLANs (SSIDs) that have the third controller as the anchor point for these WLANs. They have there management interfaces in different subnets but can ping eah other. The VLAN definition for the WLANs are diffferent on all three.

What I am seeing in the stats for mobility is a lot of handoff requests that are ignored. If I peform a 'debug mobility handoff enable' I see the following messages:

*mmListen: Jan 22 18:36:37.805: 00:37:6d:f9:48:74 Mobility packet received from:

*mmListen: Jan 22 18:36:37.805: 00:37:6d:f9:48:74   172.30.212.35, port 16666

*mmListen: Jan 22 18:36:37.805: 00:37:6d:f9:48:74   type: 3(MobileAnnounce)  subtype: 0  version: 1  xid: 4303268  seq: 27343  len 116 flags 0

*mmListen: Jan 22 18:36:37.805: 00:37:6d:f9:48:74   group id: a2423db5 e7726d89 1fc4aaff 7aea6266

*mmListen: Jan 22 18:36:37.805: 00:37:6d:f9:48:74   mobile MAC: 00:37:6d:f9:48:74, IP: 0.0.0.0, instance: 0

*mmListen: Jan 22 18:36:37.805: 00:37:6d:f9:48:74   VLAN IP: 172.30.212.35, netmask: 255.255.255.224

*mmListen: Jan 22 18:36:37.805: Switch IP: 172.30.212.35

*mmListen: Jan 22 18:36:37.805: Vlan List payload not found, ignoring ...

*mmListen: Jan 22 18:36:37.805: IP Address don't compare for client 00:37:6d:f9:48:74 is 0
*mmListen: Jan 22 18:36:37.805: 00:37:6d:f9:48:74 Ignoring Announce, client record for not found

Does this mean the mobility isn't working and if so why isn't it working?

Can anyone please tell me why these messages are occuring and whether this means there is a problem on the mobility?

I hae tested mobility by walking around the office and I do roam to other APs but I'm not sure if the above messages are indicating a problem.

Thanks,

Paul

[Scott Fella]

Well it seems like your device is roaming but when they roam to the AP on another WLC, the interface must not be defined correctly. 

So your setup is two foreign wlc's and one anchor wlc's?  Are your ap's in local mode or flexconnect?  Are all your vlans defined on all your switches?

Thanks,

Scott

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[paul.l.kyte]

Scott,

Thank you for your answer, I'll explain more to make it clearer.

APs aren't in flexconnect mode. The VLANs in use by a particular WLC is configured on the switch that it is connected to, the VLANs used by the other WLCs aren't configured on the switch. The three WLCs connect to three different switches and those switches only have the VLANs that the connected WLC uses.

The three controllers are in the same mobility group. These are WLCA, WLCB and WLCC

Two controllers WLCA and WLCB have an SSID of Corporate, the third doesn't. The VLAN behind this WLAN is 981 on WLCA and 989 on WLCB. Nothing on WLCC as already stated. There are no anchor definitions for this SSID.

On WLCA and WLCB there is an SSID of Guest and this is anchored from both to WLCC where the SSID is also configured.

What the logs are suggesting to me is that a device is trying to roam from WLCA to WLCB but is being ignored because of the reason behind the error messages.

Hopefully this helps you to understand the setup.

Do you know why the message is occuring?

Thanks,

Paul

[Stephen Rodriguez]

when a client roams, let's say from WLCA - WLCB, WLCB does not know where the client roamed from.

So it sends a Mobility Announce to all members of the mobility group.  So you will see this on a mobility peer that didn't have the client.

In your debug, which WLC did that message come from?  I'm thinking it was WLC-C

HTH,
Steve

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[paul.l.kyte]

Stephen,

The message was on WLCB, it states the address of WLCA in the messages. So it looks like WLCB was receiving a roam from WLCA but couldn't accept it because the "VLAN List Payload Not Found" and "IP address don't compare for client mac address is ip address", in these cases ip address is 0.

?????

Thanks,

Paul

[Stephen Rodriguez]

that could have been a roam from WLC-C to WLC-A.  you have to know which WLC the client was on, and which it roamed to. for this to make any sense.

as I said, on roam to a new WLC, the new WLC sends the announce to all memembers.

HTH,
Steve

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[paul.l.kyte]

Steve,

There is no possible roam from WLCC to WLCA or WLCB. It is purely an anchor WLC and has no APs.

The message states the mobility packet was received from WLC 172.30.212.35, port 16666. This is WLCA. This message is in the debug output of WLCB. So this looks to me like WLCA is sending a packet to WLCB and then WLCB is issuing the messages.

I also see messages that show a succesful handoff of a client from WLCB to WLCC. The only messages of the type attached occur from the source WLCA!

Regards,

Paul

[Stephen Rodriguez]

ok, that makes sense.

next question, do you know if when that message was sent, that was a new client coming on to WLCA?

HTH,
Steve

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[paul.l.kyte]

Steve,

I'm going to have to check this.

I've done another log and I can see some succesful mobility messages as wel as these failures. It may well be a new client associating with an AP and the controller annoucing/quering with other controllers.

I'll analyse the log and come back tomorrow.

Thanks,

Paul

[paul.l.kyte]

Steve,

I've analysed the debug log and have found that there are the following message types:

type: 3(MobileAnnounce)

type: 5(MobileHandoff)

type: 8(AnchorTransfer)

type: 9(AnchorTransferAck)

type: 10(MobileHandoffEnd)

type: 11(MobileHandoffEndAck)

type: 13(PMK-Delete)

type: 16(MobileAnchorExport)

type: 17(MobileAnchorExportAck)

The mobile announce that is received from another peer is probably due to a new client connecting to the WLAN. The local WLC doesn't have any information for this and therefore issues the message.

I have seen subsequent announce messages where the client is not known but then a handoff to WLCC has occured. This is due to this being the Anchor for the WLAN.

I haev also seen other announce messages where the client has then been transferred from WLCA to WLCB.

In the absence of anyone knowing why the VLAN Payload and ignore messages occur I am going to assume that these are normal activities when clients first connect to the WLAN.

If anyone does know why the messages occur please let me know but until then I am going to go with my opinion that these messages are normal activity.

Thanks,

Paul