Meraki MX DHCP and Windows 11

[Eri1]

Hi all,

Sorry, this might a broad question. Any insight to narrow it down is appreciated.

We have got multiple random cases where windows 11 devices suddenly assigned itself with APIPA address. It happened on multiple networks, and on random devices. (still trying to figure out how to recreate the issue and its timing). We can see these events happened on Meraki logs, like below

Source IP and/or VLAN mismatch

Client: 169.254.150.33, MAC: 24:FB:E3:EC:87:7D, VLAN: 1, details: sent 409 unexpected packets

Quick fix would be to unplug and plug the ethernet cable or restart the device or manual IP release and renew.

The only common facts about these issues were that it happened on Win 11 devices only. We have not tried a different DHCP server beside Meraki as of right now.

If anyone has experienced the same issue or any advises to help troubleshoot this are all appreciated.

[Gux]

Hello Eri1,

Do you have any VLAN's configured? Is Meraki doing the DHCP?

Are the devices connected directly to the switch or MX device? 

I have a Windows 11 Device and not had this issue. 

[Eri1]

VLANs are configured, and DHCP is running on the MX. it's connected to a switch then to the MX.

Is your device having its IP static?

[DarrenOC]

Hi @Eri1 , is the issue solely isolated to these Win11 devices?

Is your MX on the latest firmware and likewise are the Win11 machines running latest drivers?

[Eri1]

Yes, yes and yes

[ConnorL]

A quick Google shows a fair amount of folk mentioning DHCP issues on Windows 11 24h2

E.g. https://learn.microsoft.com/en-us/answers/questions/3953441/problem-in-network-windows-11-24h2?forum...

https://forum.netgate.com/topic/195657/psa-if-you-are-using-dhcp-options-with-windows-11-and-dhcp-ne...

[Brash]

We've got around 200 Lenovo's and 50 or so Surface laptops on Windows 11 24H2 and so far we haven't seen any notable issues.

Are you doing any specific DHCP options?

Are your network drivers up to date?

Does it happen regularly enough that you can capture it with a rolling packet capture?

[Eri1]

Normal options, DNS server, DNS suffix (option 15), gateway.
Yep, it is up to date

Thats the challenging part, it might happen only once a week or not happening at all. Still figuring out what's the trigger.

[BlakeRichardson]

@Eri1 what is your DHCP lease time set to? I would make it shorter and see if that helps. As others have said having a basic topology of your network would also help troubleshooting.

Are you running straight DHCP or are you statically assigning via DHCP? If not give that a give on one or two machines and see if that makes any difference. 

[Eri1]

It was set to 1 days. It's a very simple topology (MX <- Switch <- PC)

As what everyone has suggested, its more likely a windows 11 24h2 issue

[BlakeRichardson]

Most likely but just wanted to rule out a network config or topology issue. 

[JoBa]

Did this turn out to be 24H2?  I have the exact same setup (MX <- Switch <- PC), and am seeing the same thing however not all PCs are 24H2 yet so I'm still not sure.  It's mostly at one site where I'm seeing this, and I did see a user's laptop have that issue at that site, but then not at the next they went to (same network setup).

[Eri1]

We still had our suspicion on 24H2. It happened to different networks across different organizations. 

Its hard to report the issue to Microsofy as these things happened randomly