topic Re: Cisco 9800-L WLC roaming issues in Wireless

Cisco 9800-L WLC roaming issues

michaelowen — Wed, 27 Sep 2023 12:27:55 GMT

Hi all

I have an issue where when some users are roaming from 1 side of the building to the next they drop off the network and have to forget and reauthenticate. I didn't set this controller up but I can see Fast transition is adaptive enabled. So I started reading up on FT and it says Auth Key Mgmt should be FT + 802.1x where ours is set up as 802.1x. It also states flexconnect should be enabled and the AP's should all be in the same group.

I can only see a default Flex profile in WLC configuration but can seem to find anything with AP groups.

Any ideas?

Re: Cisco 9800-L WLC roaming issues

RoadRunner4k — Wed, 27 Sep 2023 13:15:18 GMT

Does the APs reside in the same "Site tag" & "Policy Tag "

Re: Cisco 9800-L WLC roaming issues

michaelowen — Wed, 27 Sep 2023 13:29:05 GMT

Hi RoadRunner

Yes both are on the same site and policy tag. I checked on the AP's and they are all set to AP Mode - Local. Most of the documents it states this should be on FlexConnect but when I click the down arrow FlexConnect isn't an option.

Re: Cisco 9800-L WLC roaming issues

michaelowen — Wed, 27 Sep 2023 14:08:59 GMT

Looking further into the way this is configured they have only ticked Neighbor list. Should Prediction Optimization and Dual band neighbor list not be ticked?

Re: Cisco 9800-L WLC roaming issues

Mark Elsen — Wed, 27 Sep 2023 14:20:32 GMT

- Have a checkup of the 9800-L configuration with the CLI command show tech wireless and feed the output into : https://cway.cisco.com/wireless-config-analyzer/

Re: Cisco 9800-L WLC roaming issues

michaelowen — Wed, 27 Sep 2023 14:54:58 GMT

Hi marce

This is so good gave me lots to look into.

Found this going to make the changes and see how it goes. I will let you know.

For best results, it is better to enable dual band support for 11k. This should only be avoided, if single band devices are present on the network. This is part of the WLAN profile

Re: Cisco 9800-L WLC roaming issues

William Foster — Tue, 19 Nov 2024 18:33:03 GMT

I have tried this and when I upload the .log file it spins for a minute then it just goes back to the same screen and it gives me no output. Does the file need to be in a different format?

Re: Cisco 9800-L WLC roaming issues

RoadRunner4k — Tue, 19 Nov 2024 18:45:28 GMT

did you use "show tech-support wireless" as input ?

Re: Cisco 9800-L WLC roaming issues

Mark Elsen — Tue, 19 Nov 2024 18:48:43 GMT

@William Foster wrote >... Does the file need to be in a different format?
No but usually the generated file from show tech wireless is saved as .txt
file ; you may want to try that ; remember do not use a simple show tech , use
the full command as pointed out in green ,

Re: Cisco 9800-L WLC roaming issues

William Foster — Tue, 19 Nov 2024 19:51:06 GMT

Well Dab Nabit changing to a .txt I ended up with the same results. I wonder if it is throwing it back because of the
date and time stamp at the beginning of each line

Re: Cisco 9800-L WLC roaming issues

Mark Elsen — Tue, 19 Nov 2024 20:01:45 GMT

- @William Foster wrote : >....Well Dab Nabit changing to a .txt I ended up with the same results. I wonder if it is throwing it back because of the date and time stamp at the beginning of each line

- That should not happen and is not included behavior indeed, it means that you are using some terminal operator tool which does that , try changing to something else such as PuTTY or standard SSH access (connection)

Re: Cisco 9800-L WLC roaming issues

Rich R — Tue, 19 Nov 2024 23:03:56 GMT

Exactly as @Mark Elsen says - you must be using some sort of terminal or editor which is inserting date and time stamps which will definitely break the tool. You must use the actual raw "show tech wireless" output from the WLC. Do not alter it in any way.

Re: Cisco 9800-L WLC roaming issues

William Foster — Wed, 20 Nov 2024 00:16:45 GMT

Thanks my Secure CRT was doing it for some reason, but I have since corrected it. That is a pretty awesome tool. I have been having issues at a site whose wireless coverage is extremely good. I am noticing that users that are complaining are jumping between 3 APs that are closest to them. I am guessing it is roaming causing this issue. It's odd that roaming would cause them to drop though. I was remoted into a user and confirmed they are definitely dropping when they roam to a different AP. Below is what the tool you suggested produced for me.

Optimized Roaming: Optimized Roaming is enabled, this could cause roaming failures in multiple scenarios. It is recommended to use 802.11k/v roaming instead. Reported for Band(s): 2.4 GHz 5 GHz
Action: Disable the feature using the command ap dot11 5ghz/24ghz rrm optimized-roam. New devices will use 11k/v information when present

Roaming: There are denied client roamings across different policy profiles. It is advisable to enable client vlan-persistent command to improve roaming experience
Action: By default, it is not allowed to roam on same WLAN over different policy profiles. This leads to client delete and a new on boarding is required. Use the command wireless client vlan-persistent on 17.3.4 or higher, to improve roaming.

We are running 17.9.5. Do you have any experience on the above suggestions?

Re: Cisco 9800-L WLC roaming issues

Rich R — Wed, 20 Nov 2024 00:43:02 GMT

That advice is provided because those are common mistakes. You are well advised to follow it. Refer to the config guide if you want more info on the commands.

Optimized Roaming is covered in the Best Practices guide (link below). A lot of the advice from the tool is based on the guide. https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/technical-reference/c9800-best-practices.html#Optimizedroaming

Roaming between policy tags is also covered there: https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/technical-reference/c9800-best-practices.html#Roamingbetweenpolicytags

As already advised refer to the TAC recommended code versions (link below) because 17.9.x is approaching end of life.

Re: Cisco 9800-L WLC roaming issues

Mark Elsen — Wed, 20 Nov 2024 07:02:24 GMT

@William Foster wrote : >...We are running 17.9.5. Do you have any experience on the above suggestions?
No detailed experience ,it comes down to toggling those parameters and observe the result, also note that client roaming decisions are always autonomous ; also make sure that the driver(s) of the wireless card(s) are up to date.
You can also adjust the wireless roaming sensitivity on the adapter ,