WLC Client Roaming Between APs

I have a single WLC with AP1231's. I have clients associating to one AP, but they are not always re-associating to an alternate AP as always desired when roaming to an alternate location. Is there a way to adjust how clients associate to an alternate AP based on better signal strength of a closer AP?

The best place to look for the commands, is in the command reference for your specific version as they do vary quite a bit from version to version.
There are also client settings on the adaptor which dictate how the client behaves, on the Intel client you can change the conditions which cause the client to roam, I am also assuming that you have good wireless coverage otherwise the clients will tend to stick to the one cell, there are various settings on the controller to adjust for performance and coverage, there is one setting which says it can adjust the power settings on the client, I would check the notebook supplied as I recently did worth with an IBM which required a patch.
On the Intel client under advance there is a setting called ?Roaming Aggressiveness?
Best of luck

Similar Messages

Roaming between APs with Radius

Hi everyone,
Someone told me about this issue this week. I heard that roaming between APs was not possible without reauthenticating when RADIUS authentication is used. This means that you need to reauthenticate yourself to the RADIUS server each time you switch from an AP to another, so you have to re-enter your credentials many times.
Do someone have heard about the same thing? Is there some technical articles discussing about this issue?
Thx, Jim

With LEAP authentication, your credentials are cached (encrypted) from when you login to windows.
Wen you LEAP authenticate those cached credentials are used, and when you roam they are used to reauthenticate.
The user is not prompted for username-password when roaming with LEAP.
The best security white-paper is this one;
http://www.cisco.com/warp/customer/cc/pd/witc/ao1200ap/prodlit/wswpf_wp.htm

Roaming between APs

Please advise me on this. I have four 1200 Access Points with the latest firmware. They are on the same subnet. When I am associated with an AP the signal strength is Excellent. As I move far away from the AP the signal decreases to Fair. I am close to another AP, but my laptop drops off the network before it associates with the second AP. Is there a setting that I can change so that when I roam, I associate with the closest AP before I drop off the network. I am using CISCO 350 wireless cards.
Thanks,

Roaming is determined by wireless clients, not the APs.
Please go to ACU, click on "Profile Manager". Select the profile in the pull down menu and click on "Edit"
A new window will pop up. Click on "RF Network". There are two settings to control the roaming:
"When Adapter Has been Asscocited For At Least" "And Signal Strength Is Less Than"
I assume that you use ACU version 6.3 in Windows. There should be a similar setting. Please reply with the ACU version and operating system if you do not find the parameters.

Airplay streams drop/skip when clients roam between Lightweight APs

Hello,
We are currently running a WLC2106 w/ 3 1131 APs and in areas where coverage over laps our client airplay streams are skipping. I think this is caused when the client (iphone/ipad) switches APs. All ap's are setup in local mode and should support fast roaming correct? I am thinking the multi-cast settings are not properly setup or my ap is not configured correctly?
Controller --> General Ap Multicast mode = multicast w/ 239.0.0.0 group address, broadcast forwarding enabled.
enable global multicast mode, and enable igmp snooping are both checked.
Data rates on apps 1-11mbps disabled, 12 mandatory and all greater rates supported. P2p blocking action disabled
Thanks for the help!

We have two WLANS one with WPA2 PSK the other with WPA2 Auth 802.1X. The airplay devices are on the WPA2 SSID and the clients on the 802.1x, both go to the same vlan. Should I move all clients to the WPA2 SSID?
Thanks for the response,
David

Roaming between APs causes reauthenticaion w/ CCKM

I have a small set up with a 2106 controller and two 1252AG access points.
Each AP is on a side of a floor less than 100' from each other. But with columns and partitions in the way they just barely overlap one another.
I have 2 WLANs configured with [WPA + WPA2][Auth(802.1X + CCKM)] (One is for N and one is for B/G). Testing is being performed with a MacBook Pro. When I roam from one AP to the other I am still prompted to reauthenticate.
Does the MBP not support CCKM? Perhaps the fact we are using token based auth?

CCKM-authenticated client devices can roam from one AP to another without any perceptible delay during reassociation. An AP on the network provides Wireless Domain Services (WDS) and creates a cache of security credentials for CCKM-enabled client devices on the subnet. The WDS APs cache of credentials dramatically reduces the time required for re-association when a CCKM-enabled client device roams to a new AP. When a client device roams, the WDS AP forwards the client's security credentials to the new AP. The re-association process is reduced to a two-packet exchange between the roaming client and the new AP. Roaming clients reassociate so quickly that there is no perceptible delay in voice or other time-sensitive applications.

How to improve client handover and roaming between AP's

Improving client Handover and roaming between APs
There are a few standards and methodologies available to use to improve handover of clients between APs. Most are focused on VOIP technologies, but it must always be remembered that we cannot control the client Handover (especially with legacy clients) we can only encourage them. Some Standards and methods work well for some environments and some do not - test the recommendations extensively before implementing in a live Production environment. It must also be noted that all settings take effect immediately once applied, however from a client perspective it might need to re-associate for the changes to take effect client side.
As with everything else in IT, if a perfect method/solution existed there would only be one - try them all and keep the best.
The Standards and Definitions
802.11k
IEEE 802.11k allows a device to quickly identify nearby APs that are available for roaming. When the signal strength of the current AP weakens and the device needs to roam to a new AP, it will already know the best candidate AP with which to connect to.
802.11r
IEEE 802.11r specifies fast Basic Service Set (BSS) transitions between access points by redefining the security key negotiation protocol, allowing both the negotiation and requests for wireless resources to occur in parallel.
When a device roams from one AP to another on the same network, 802.11r streamlines the authentication process. BSS allows a devices to associate with APs more quickly. Coupled with 802.11k's ability to quickly identify the target AP, BSS's faster association method may enhance application performance.
Handoff Assist
The AP monitors the RSSI for every associated client. If the RSSI for a specific client falls below "low-rssi-threshold" and continues to fall for the "rssi-falloff-wait-time", then the AP will send a de-auth to the client.
The de-auth is meant to kick the client away from the current AP and get it to re-authenticate to a nearby AP. This will have the effect of helping a client handover between 2 APs.
BUT (Big But), if the client gets de-authed and takes a while to re-authenticate (if it even does re-authenticate automatically after a de-auth), then this will have the effect of destroying communication instead of helping it -- mostly found with legacy clients.
Remove Lower Transmit Rates
Removing lower transmit rates is a way to promote better roaming, BUT not all clients respond well, or even respond to it.
The practice is that the basic rates are a subset of the transmit rates. If you only want to allow speeds 9 and up, you would select only the transmit rates of 9 and up, and the basic rates of 9 and 11. If a legacy client expects the rates of 1 and 2 it will not connect.
Local Probe Threshold
Local probe Threshold prevents a client from connecting to an AP with a too low a signal - helps more with initial connection than roaming.
The local probe threshold parameter is not supposed to force clients to roam as soon as they pass near an access point with a good signal, but rather to NOT hold on to an access point with a weak signal (avoiding sticky clients).
PMK Caching
Defined by 802.11i and is a technique available for authentication between a single AP and a station. If a station has authenticated to an AP, roams away from that AP, and comes back, it does not need to perform a full authentication exchange. Only the 802.11i 4-way handshake is performed to establish transient encryption keys.
Opportunistic Key Caching (OKC)
Is a similar technique to PMK, but not defined by 802.11i, for authentication between multiple APs in a network where those APs are under common administrative control. An Aruba deployment with multiple APs under the control of a single controller is one such example. Using OKC, a station roaming to any AP in the network will not have to complete a full authentication exchange, but will instead just perform the 4-way handshake to establish transient encryption keys
Implementation and Configuration
802.11k
802.11k is configured in your VAP profile. Tick the option to “Advertise 802.11k”. There after set the Handover Trigger Feature Settings.
Tick the “Enable Handover Trigger feature” and then set RSSI threshold by specifying the -dBm level at what the hand over trigger should be sent to the client
802.11r
802.11r is configured under SSID of your VAP profile. Tick the option to “Advertise 802.11r”
HandofF Assist
Station Handoff Assist is enabled in RF Optimization under the RF Management section of AP configuration.
Tick the “Station Handoff Assist” option to enable it, next set the Low RSSI Threshold – the threshold determines above what level no deauth gets sent
Lower Transmit Rates
Transmit rates can be adjusted in the Advanced tab of SSID under your VAP profile.
Remember that the basic rates are a subset of the transmit rates. If you only want to allow speeds 9 and up, you would select only the transmit rates of 9 and up, and the basic rates of 9 and 11
Local Probe threshold
Local Probe threshold can be adjusted in the advanced tab of SSID under your VAP profile.
Depending on the density of your APs consider values between 20 and 40 -- 40 being aggressive in an AP dense area.
Deny Broadcast Probes
Denying Broadcast Probes can cause problems with Roaming especially if the SSID is hidden – leave option disabled.

Hi, thank you for the helpful guidance. I have a basic question, if the device roam from one AP to another AP with the same SSID. Is there a need of re-authentication given a) the network uses EAP based authentication; b) the network uses MAC address authentication. If there is no need of EAP re-authentication, how the 802.11 keys are moved to the new AP. Thank you very much if you could help me clarify my thought.

Client Roaming Within Single WLC with Different AP Groups

I am trying to setup a 4400 WLC with 2 different AP Groups mapped to its respective Dynamic Interfaces / Vlans. AP's are equally mapped to both the AP groups by Floor wise ex: First floor AP's connect to one AP group and the Second Floor AP's connecting to other AP group.
Goal is to create separate Network policy for each Floor using ACL's and apply to their respective Vlans on Layer 3 Switch. Wireless Raoming should happen seamlessly between these Ap groups making the DHCP changes by not disconnecting and connecting every time user roam across the Floors.
Problem is When Clients Roam between Floors i,e moving between AP Groups, they still maintain their old DHCP IP addresses when moved to new AP group even after Client re-authetication. This defies our goal of creating a Wireless Network Policy using single WLC.
Knobs i have tuned in WLC to acheive our goal includes....
1. WLAN Session Timeout - No use
2. DHCP Proxy Disable - No Use
3. ARP Time out - No use
Looks like WLC is storing the IP address and MAC information of the Client unconditonally during roaming and clearing out untill a manual or forced disconnect or disassociation is done.
Did anyone tried to implement this setup and made it running? Any help or suggestion would be higly appreciated.
Thanks
Guru

abit late for a reply but....try going to the SSID>Advanced and ticking the "DHCP Addr. Assignment" Required checkbox and test again.
What does the DHCP Required field under a WLAN signify?
A. DHCP Required is an option that can be enabled for a WLAN. It necessitates that all clients that associate to that particular WLAN obtain IP addresses through DHCP. Clients with static IP addresses are not allowed to associate to the WLAN. This option is found under the Advanced tab of a WLAN. WLC allows the traffic to/from a client only if its IP address is present in the MSCB table of the WLC. WLC records the IP address of a client during its DHCP Request or DHCP Renew. This requires that a client renews its IP address every time it re-associates to the WLC because every time the client disassociates as a part of its roam process or session timeout, its entry is erased from the MSCB table. The client must again re-authenticate and reassociate to the WLC, which again makes the client entry in the table.

Voice gaps in cisco ip phones 7921 when roaming between cisco APs

The following problem is faced when cisco ip phones 7921 are roaming between APs:
When a call is establishedon wireless ip phones, and the phones are roaming between APs, a three seconds gap appears but the call doesn't disconnect.
The following log messages are displayed on both APs:
The first AP:
*Mar 1 23:30:30.493: %DOT11-6-DISASSOC: Interface Dot11Radio0, Deauthenticating Station 001e.4a3f.c5b8 Reason: Sending station has left the BSS
*Mar 1 23:30:30.956: %DOT11-4-MAXRETRIES: Packet to client 001e.4a3f.c5b8 reached max retries, removing the client
*Mar 1 23:30:30.957: Client 001e.4a3f.c5b8 failed: reached maximum retries
The second AP:
*Mar 1 23:33:40.049: %DOT11-6-ASSOC: Interface Dot11Radio0, Station SEP001E4A3FC5B8 001e.4a3f.c5b8 Associated KEY_MGMT[WPA PSK]
What can be the problem?
Thanks

That above error message is frequently associated with another error message "%DOT11-6- DISASSOC: Interface Dot11Radio0, Deauthenticating Station
Reason: Sending station has left the BSS ". This occurs because of the Interference from the adjacent access point. So change the channel and adjust the excessive power on the access points so that there is no too much overlap on the access points coverage cells.

Roaming between Flexconnect groups for scaling

I have a customer that needs flexconnect at each of his 10 locations to access local servers and printers. The customer has a pair of 5508 WLCs running 7.6.130.0.
While the customer currently has 25 and under AP count per site, they are considering an expansion to 50 - 60 per site.
We are considering the mobility agent on 3650/3850/4500 switches, but the multi-hop restriction will drive the cost too high.
What is the downside for defining multiple flexconnect groups per site?
The customer is also considering Unified Communications. For example, would the voice RTP stream on a wireless IP phone roaming between APs on different flexconnect groups appear to be seamless?

If you plan on utilizing any real-time applications such as voice, you would not want these devices to be roaming between FlexConnect Groups. There will be a full re-authentication of the client; with the exception of OKC capable machines, which "may" roam more cleanly. This means some standard data clients may perform a fast roam, or at least not notice much of a hiccup even with a full re-auth.
In either scenario, you would want to make sure this is NOT a L3 mobility roam (ie. FlexConnect WLAN/VLAN mapping to different networks). This will cause major problems for all your clients as they will most likely end up talking on the new VLAN with their old IP address.
Mobility / Roaming Scenarios
WLAN Configuration
Local Switching
Central Switching
CCKM
PMK (OKC)
Others
CCKM
PMK (OKC)
Others
Mobility Between Same Flex Group
Fast Roam(1)
Fast Roam(1)
Full Auth(1)
Fast Roam
Fast Roam
Full Auth
Mobility Between Different Flex Group
Full Auth(1)
Fast Roam(1)
Full Auth(1)
Full Auth
Fast Roam
Full Auth
Inter Controller Mobility
N/A
N/A
N/A
Full Auth
Fast Roam
Full Auth
(1) Provided WLAN is mapped to the same VLAN (same subnet).

Roaming between RV220W wireless router and WAP121 Access Point

Hello, I have recently purchased a RV220W wireless router and a WAP121 access point and i would like to allow my users to "roam" between the two networks as needed (so when the user is closer to whichever one they connect to that one since it has a better signal). For the most part I only have experience in cisco IOS and in actual routers not the wireless stuff so my knowledge has not exactly transfered over well.

William,
WDS will not work between the RV220W and WAP121 due to incompatible chipsets. The RV220W can be repeated using WDS by another RV220W or RV180W only. You will need to plug the WAP121 into the RV220W or try WorkGroup Bridge mode to repeat the signal.
Regarding roaming, the router or AP are not aware of each other and do not have the capability to disconnect a client and help them connect to the AP with the stronger signal. The client will switch to the stronger AP only when the original signal is lost.
The Aironet (enterprise) devices have the ability to utilize a wireless LAN controller which can help keep devices connected to the stronger signal and allow truly seamless roaming between APs.
- Marty

Roaming between radios

Hello to all!!
I`d like to know if roaming it's possible between radios. I mean: I've some ap with radio a and b/g/n and other only with b/g/n, client roaming between them is possible??
thanks in advance!!

to add to Leo, so long as you have overlap and the SSID are configured the same, you should roam just fine between AP.
HTH,
Steve
Please remember to rate useful posts, and mark questions as answered

Roaming between mesh and non mesh and mesh AP design

Hi There,
I need some verification on the following:
- Can client roam between Mesh AP 1550 series and Non-Mesh AP?
- I have 1550 series AP to be installed and all the mounting area are with data point ready, which connects back to switch. Would configuring mesh for this outdoor units recommended, and guide on this. Current guide i am looking from cisco site is basically the AP do not have wired ethernet connection, my design here a bit different, all the AP's have wired connection back to the switch.
Kindly assist.
Thank you
Rama

I have seen and done installs like this. The advantage is that you don't have to worry about the backhaul dropping. So it's like any LAP but big chunky outdoor AP. If the RAP looses Ethernet connectivity... Well it changes to a MAP. So you can look at
It as a benefit. It's always nice to be able to have Ethernet when you can.
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Difference in client tables between WLC and AP controller d0

Hello gang,
Anyone know whether its normal to have an APs' d0/d1 controller output show clients that don't appear on the WLC's "sh client <AP>" output?
Here's an example - 10 clients visible from a "sh client " on the controller, but 15 clients visible on AP4s "sh controller d0" debug.
Granted the User Idle Timeout has been bumped up to 7200 seconds, but shouldn't the AP's d0/1 client table get updated if/when a client roams to another AP nonetheless? Wouldn't this otherwise cause confusion? Is the Split-MAC Split-brained?
Thanks for your input,
--Bruce Johnson
(mcores2wlc1) >show client ap 802.11b mell9s1ap4
MAC Address AP Id Status WLAN Id Authenticated
00:40:9d:31:b0:79 130 Associated 6 Yes
00:40:9d:34:1f:04 130 Associated 6 Yes
00:40:9d:33:ee:04 130 Associated 6 Yes
00:40:9d:2b:d1:6a 130 Associated 6 Yes
00:40:9d:31:23:a3 130 Associated 6 Yes
00:40:9d:33:e9:28 130 Associated 6 Yes
00:40:9d:31:27:a5 130 Associated 6 Yes
00:40:9d:33:eb:4b 130 Associated 6 Yes
00:40:9d:31:22:1d 130 Associated 6 Yes
00:40:9d:33:ee:cb 130 Associated 6 Yes
(mcores2wlc1) >debug ap command "sh cont d0" mell9s1ap4
(mcores2wlc1) >Thu Feb 26 18:54:10 2009: mell9s1ap4:
Thu Feb 26 18:54:10 2009: mell9s1ap4: ---Clients AID VLAN Status Age Tx Mode Enc Key Rate
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d33.eaec 198 6 0000 0800000FF 7195/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d30.efd1 197 6 0000 0800000FF 7195/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d31.bc74 195 6 0000 2800001FF 7165/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d31.27a5 193 6 0000 0800000FF 7195/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d33.eecb 192 6 0000 2800000FF 7195/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d31.221d 190 6 0000 0800000FF 7194/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d33.eb4b 186 6 0000 0800000FF 7194/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0016.6faf.9d64 185 3 0000 0C00000FF 7186/7200 0-0 0191 200 0-10 10FC0000 06C
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d33.e928 177 6 0000 2800001FF 5818/7200 0-0 10111 200 0-10 10000000 016
=>Thu Feb 26 18:54:10 2009: mell9s1ap4: 0016.6faf.9db8 176 3 0000 0C00000FF 7140/7200 0-0 0191 200 0-10 10FC0000 06C
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d31.23a3 174 6 0000 2800000FF 7195/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d2b.d16a 165 6 0000 1800000FF 7194/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d33.ee04 163 6 0000 0800000FF 7194/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d34.1f04 151 6 0000 1800000FF 7195/7200 0-0 10111 200 0-10 10000000 016
Thu Feb 26 18:54:10 2009: mell9s1ap4: 0040.9d31.b079 147 6 0000 2800000FF 7194/7200 0-0 10111 200 0-10 10000000 016

hi Leo,
I tested this out, but i guess its not working as i thought it would work. I configured the backup primary controller IP and name in the global configuration of the Wireless tab of the WLC and left the AP high availability blank with no settings. I joined the AP to the WLC and show capwap client ha output on the AP shows the backup primary controller name. but if i shut down the primary controller, the AP does not join the back, it just tries to get WLC ip by renewing DHCP forever and stuck in that...   below are the outputs.. any idea why its like this ? I thot if there is no HA configured at the AP level, the global config on the controller level should take effect ?
LWAP3-1042#sh cap cli ha
fastHeartbeatTmr(sec)   7 (enabled)
primaryDiscoverTmr(sec) 30
primaryBackupWlcIp      0xA0A700A
primaryBackupWlcName    WLC2-4402-50
secondaryBackupWlcIp    0x0
secondaryBackupWlcName
DHCP renew try count    0
Fwd traffic stats get   0
Fast Heartbeat sent     0
Discovery attempt      0
Backup WLC array:
LWAP3-1042#
*Apr 30 20:36:21.324: %CAPWAP-3-DHCP_RENEW: Could not discover WLC using DHCP IP. Renewing DHCP IP.
Not in Bound state.
*Apr 30 20:36:31.829: %DHCP-6-ADDRESS_ASSIGN: Interface GigabitEthernet0 assigned DHCP address 10.10.114.49, mask 255.255.255.0, hostname LWAP3-1042
*Apr 30 20:37:17.832: %CAPWAP-3-DHCP_RENEW: Could not discover WLC using DHCP IP. Renewing DHCP IP.
Not in Bound state.
*Apr 30 20:37:28.337: %DHCP-6-ADDRESS_ASSIGN: Interface GigabitEthernet0 assigned DHCP address 10.10.114.50, mask 255.255.255.0, hostname LWAP3-1042
*Apr 30 20:38:14.338: %CAPWAP-3-DHCP_RENEW: Could not discover WLC using DHCP IP. Renewing DHCP IP.
Not in Bound state.
*Apr 30 20:38:24.842: %DHCP-6-ADDRESS_ASSIGN: Interface GigabitEthernet0 assigned DHCP address 10.10.114.51, mask 255.255.255.0, hostname LWAP3-1042
regards
Joe

Inter-Controller and Inter-Subnet Roaming between WLC 4402 and 5508?

Hi!
Will it support roaming between WLC 5508 ver. 7.0 and WLC 4402 ver. 4.2?

Here is the matrix for support of IRCM, but the answer is yes.
http://www.cisco.com/en/US/docs/wireless/controller/5500/tech_notes/Wireless_Software_Compatibility_Matrix.html#wp116668
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7920 roaming between two WLCs

hi,
- i have two WLCs 4404 and 4402 in the same mobility group and all connections seem to be ok.
- one ssid for voip.
- two 7920 phones
when i roam between the WLCs i will lose the connection.
What should i configure on the WLC??
thx

Are you doing L3 mobility?
If so, would configure the voice ssid for the same VLAN on both controllers to see if that works or not.
Of course for mobility group setup, need the mac and IP configured on each contoller in that mobility group.
Ensure that 3.02 is loaded on the 7920 phones.
Would recommend 4.0.217.0 or later for the controller version.
Refer to WLAN SRND for more info.
http://www.cisco.com/univercd/cc/td/doc/solution/emblty30.pdf

WLC Client Roaming Between APs

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