Disable the use of IPV6 in cisco 9800-CL

Chandan Singh · ‎01-05-2025

Is there a way we can disable the use or display of IPv6 in cisco WLC 9800-CL.

if anyone has idea why Ipv6 is also allocated to clients ,when not being used.

MHM Cisco World · ‎01-05-2025

the VLAN SVI config in Core SW from there disable IPv6

MHM

Chandan Singh · ‎01-05-2025

Can it be done from WLC end ?

MHM Cisco World · ‎01-05-2025

If DHCP is run on core SW then it control the IPv6 assign to wifi client.

MHM

marce1000 · ‎01-05-2025

- It will be off by default when not configured ; clients usually show default link local addresses , unrelated to the WLC,

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

heysmirk03 · ‎01-06-2025

You say it's a flat network. Is the SVI you are managing the C9800 on the same VLAN as your SSID and clients are? I suspect the C9800 is consuming the IPv6 packets. Separate it out. Use a unique VLAN to manage the C9800, attach your SSID to a different VLAN and don't create an SVI on the C9800 for it, just create the L2 VLAN.

https://9apps.ooo/

Rich R · ‎01-06-2025

The only way to stop a client giving itself an IPv6 address is to disable IPv6 on the client.
The advice from the others already covers the other possibilities.

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TAC recommended codes for AireOS WLC's and TAC recommended codes for 9800 WLC's
Best Practices for AireOS WLC's, Best Practices for 9800 WLC's and Cisco Wireless compatibility matrix
Check your 9800 WLC config with Wireless Config Analyzer using "show tech wireless" output or "config paging disable" then "show run-config" output on AireOS and use Wireless Debug Analyzer to analyze your WLC client debugs
Field Notice: FN63942 APs and WLCs Fail to Create CAPWAP Connections Due to Certificate Expiration
Field Notice: FN72424 Later Versions of WiFi 6 APs Fail to Join WLC - Software Upgrade Required
Field Notice: FN72524 IOS APs stuck in downloading state after 4 Dec 2022 due to Certificate Expired
- Fixed in 8.10.196.0, latest 9800 releases, 8.5.182.12 (8.5.182.13 for 3504) and 8.5.182.109 (IRCM, 8.5.182.111 for 3504)
Field Notice: FN70479 AP Fails to Join or Joins with 1 Radio due to Country Mismatch, RMA needed
How to avoid boot loop due to corrupted image on Wave 2 and Catalyst 11ax Access Points (CSCvx32806)
Field Notice: FN74035 - Wave2 APs DFS May Not Detect Radar After Channel Availability Check Time
Leo's list of bugs affecting 2800/3800/4800/1560 APs
Default AP console baud rate from 17.12.x is 115200 - introduced by CSCwe88390

Haydn Andrews · ‎01-06-2025

I think you will find the IPv6 addresses are link local (self assigned by the clients) do they all start with fe80?

If thats the case only way to disable it is to do it on the client

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lukaszdaczkowski · ‎01-22-2025

Hello Chandan

You can use this command:

conf t
no wireless ipv6 client

LAB-9800-1(config)#no wireless ipv6 ?
client Disable wireless client IPv6 traffic on Wireless controller
(centrally switched)
nd Configure wireless IPv6 ND parameters
ra Configure wireless IPv6 RA parameters

BR

Luke

Paccers · ‎02-18-2025

Same problem being experienced for us with 9800-CLs in Azure. We migrated from AireOS where no IPv6 IPs were learned or being forwarded, we now have many clients showing with fe80 IPv6 addresses and they are also being passed on to firewalls via Framed-IPv6-Address value in RADIUS Accounting packets. We're using the same Flex w/ central auth & local switching setup as we did with AireOS and haven't changed anything on local switch SVIs, this has come about since 9800 migration.

@Chandan Singhdid you find a solution in the end?