topic Re: IP "flapping"? in ExtremeCloud IQ

IP "flapping"?

ISC-Admin — Wed, 15 May 2024 19:23:03 GMT

Hi!

We've been facing this issue lately. Since we just enabled the Client Monitor option, I can't tell you when it started. It's a school environment with 7 VLANs, where each building has its designated VLAN. Every time roaming happens, some clients complain about not being able to connect to the WiFi. Then, XIQ shows us this networking issue called 'Incorrect static IP or gateway.' Digging a little deeper, I've found this:

The three IPs in the image are from three different VLANs and in this case it ended with an IP from a different VLAN, causing it to not be able to browse the internet. Has anyone experienced this kind of issue before? I've checked the DHCP logs and couldn't find anything unusual (there were some DNS update request failed errors due to the DNS update requests queue limit being exceeded, but nothing else).

Thank you in advance!

Re: IP "flapping"?

DeVoID — Thu, 16 May 2024 13:09:49 GMT

Ive had port flapping, not IP though.

But your management IP has access to all those vlans within XIQ right? because the clients have to get back to the DHCP server, which I assume is a different "Core" VLAN.

Re: IP "flapping"?

DeVoID — Thu, 16 May 2024 13:11:14 GMT

Oh, and Id recommend putting static IP's in your AP's and then just exclude the range within DHCP. No need to do a reservation for each one, etc.

Re: IP "flapping"?

Christoph_S — Thu, 16 May 2024 13:34:13 GMT

See if enabling Layer 3 roaming helps: Click on the user profile in the SSID and go to Traffic Tunneling > Enable Traffic Tunneling (GRE) > Check the Layer 3 Roaming radio button > Save User profile and push to the APs.

BR,

Re: IP "flapping"?

ISC-Admin — Thu, 16 May 2024 14:20:38 GMT

Hi!

In the 'average network traffic is less than' field, what value do you recommend?

Re: IP "flapping"?

ISC-Admin — Thu, 16 May 2024 14:33:19 GMT

Hi!

'Port flapping' was the best term I could think of to describe it, LOL. I'm only familiar with port flapping too.

"But your management IP has access to all those VLANs within XIQ, right?" - Yes, it does have access. The DHCP server is indeed on another VLAN.

"I'd recommend assigning static IPs to your APs and then just excluding that range within DHCP." - They already have static IPs from their own subnet. So basically, the DHCP server is on a separate VLAN, and the APs have a management VLAN plus a building VLAN.

Re: IP "flapping"?

DeVoID — Thu, 16 May 2024 16:37:31 GMT

Gotcha. Well Chris who replied to you knows his stuff, and i sure will get back to you on that number needed... Good luck to you.

Re: IP "flapping"?

ISC-Admin — Thu, 16 May 2024 16:40:50 GMT

Thank you anyway

Re: IP "flapping"?

ISC-Admin — Mon, 20 May 2024 11:32:48 GMT

Hello,

I tested with the default values, but it didn't solve the issue. Clients are still changing their IP 3 times in only a second, and the last IP associated with the station is still from a different VLAN from where the client is connected. A quick fix for now is to turn the WiFi off and on again, but this is not an ideal solution.

Re: IP "flapping"?

ISC-Admin — Tue, 02 Jul 2024 17:33:07 GMT

Sadly, this was not the solution. We still have this issue happening on our network.