01-21-2019 09:10 AM - edited 07-05-2021 09:43 AM
Hi All,
we see the Effect that from time to time an associated WiFi Client lost its Subnetmask and Gateway Information. Take a look:
The Client is still connected. SSID is configured with .1x and AAA Override. WLC Code is 8.8.
Does anyone know under which Circumstances this could happen?
BR, Michael
01-21-2019 10:44 AM
01-21-2019 11:07 AM - edited 01-21-2019 11:14 AM
Yes, the Client is still in RUN State. .1x is OK, and by tracing DHCP Packets everything seems also to be OK. The difficult thing is, that we talk about a Campus with 4000 AP and 8000+ Clients, and the issue is coming randomly, so its hard to catch ...
// Mike
01-22-2019 07:17 AM
01-22-2019 07:56 AM
01-22-2019 08:00 AM
01-22-2019 08:03 AM
01-21-2019 12:22 PM
How is your DHCP lease time configured? How is your SSID Advance Tab --- > DHCP Addr Assignment configured? How is your session-timeout configured for the specific SSID?
01-21-2019 01:10 PM
Hi, DHCP Lease is 1 Day (Customer Decision), DHCP Address is not Required, since some Clients (WGB) are still connected with Static IP. Session Timeout is 1800sec and - via AAA Override - 68400sec for VoIP Clients. The Corporate SSID is a single SSID approach, there is one .1x SSID and one Open /wo Auth and 3rd Party Captive Portal. Only Corporate Clients (ca 1800 Clients) are affected.
BR, Michael
01-21-2019 01:26 PM
Is that 30 min session-timeout for the corporative clients? I experienced a similar issue and I realized based on Cisco ISE logs that my disconnection happened every 8 hours (session-timeout). I suspect this timer is causing you this intermittent and random issue.
01-21-2019 02:18 PM
Yes, 30min Session Timeout are the default for the Corporate SSID, for VoWLAN Clients its 68400 per AAA Override. What were your Settings?
01-21-2019 02:36 PM
Well that might be one reason you see that. The client might be in sleep mode and doesn’t want to request dhcp and thus you see what you do. 30 minutes is too low and I’m not a fan of lowering dhcp lease times especially if the reason is because they don’t want to increase the subnet. I can see clients having issues if you have WGB’s and or specific devices with old NIC or drivers.
01-22-2019 11:50 AM
OK, thanks to everyone who invests Time on my Issue. BR, Michael
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