IP "flapping"?

[ISC-Admin]

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!

[systemscsn · Accepted solution]

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.

[ISC-Admin · Accepted solution]

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

[systemscsn]

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.

J

[ISC-Admin]

Thank you anyway

[ISC-Admin]

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.

[systemscsn]

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.