DHCP reserved clients and 9800 WLC 17.3.6

[tiluna]

Hello,

We have a strange behavior so far that we noticed with Xbox and PS4 gaming consoles on our wireless network.

We are running a 9800 WLC 17.3.6 on an open guest SSID with DHCP required option enabled.  For the Xbox and PS4 we have a DHCP reserved IP (correct MAC addresses) in our Bluecat DHCP server.  The clients will initially pick up the correct DHCP reserved IP but after several days they may/may not pick up the same IP on the same VLAN.  Has anyone seen this behavior before and can advised what I can do to resolve this?

Thank you

[balaji.bandi]

Maybe reserve the IP address for some situations or increase the leased time if you have enough IP addresses.

[eglinsky2012]

Do these devices use MAC address randomization? Are there other device types that do reliably obtain the IP address reserved for them?

[Rich R]

There are a few bugs around wrong VLAN especially with anchor designs and/or vlan override and although they say fixed don't give fixed versions!

Get a full radioactive trace on the affected clients then open a TAC case and let TAC work out why it's happening.  Also use the https://cway.cisco.com/wireless-debug-analyzer/

Are they getting another IP on the same VLAN or a completely wrong IP on a different VLAN?  If it's simply another IP on the same vlan then the client might be rejecting the IP or there might be a conflict detected.  You'll see that in a packet capture.  Make sure you don't have any network ACLs preventing DHCP renew.  (I've mentioned it before: our IT team inadvertently deployed a Windows firewall rule at one point which prevented DHCP renew so lease always had to expire then start DORA again disrupting service for users.)