MAC flapping

[berniebbow1]

I have a strange situation where wireless AP's MAC flaps between trunks a on switch.
Flapping occurs in AP's management vlan (VLAN ID 99).
Also AP's MAC is seen in data VLANs (VLAD ID 10 and 20).
AP is Ubiquity and switch is Catalyst 3750 G (15.0-2.SE10a)

I have dozens of these APs with the same setup (in other stacks) and not experiencing the issue.
It all started after adding SG350 switch and trunk between 3750 and SG350.
AP has the same configuration as others.

sh mac address-table | i fcec.da4a.4bfa
20    fcec.da4a.4a9a    DYNAMIC     Gi1/0/46
99    fcec.da4a.4a9a    DYNAMIC     Gi1/0/46
10    fcec.da4a.4a9a    DYNAMIC     Gi1/0/46

sh run int gi1/0/46

interface GigabitEthernet1/0/46
description WIFI_L21
switchport trunk encapsulation dot1q
switchport trunk native vlan 99
switchport trunk allowed vlan 10,20,99
switchport mode trunk
switchport nonegotiate
no cdp enable
spanning-tree portfast
spanning-tree bpdufilter enable

[paul driver]

Hello

Usually in a WLAN network infrequent MACFLAPs as nothing to worry about its just the switch stating that it seeing a client mac address on a different port than if has cached in its cam table, Usually this occurs when a wlan client has roamed onto another WAP, However if this occurring consistently then its a possible indication of a loop in your network.

Now looking at your port confg you have bpdufilter enabled which is defiantly not a good idea as this basically turns off spanning-tree as such you can even be more susceptible to loops something you don't want to happen, so i would recommend removing bpdufilter.

[Georg Pauwen]

Hello,

what does your topology look like, that is, what is connected to what ? Post a schematic drawing of your setup...

[berniebbow1]

%SW_MATM-4-MACFLAP_NOTIF: Host 788a.208c.xxxx in vlan 99 is flapping between port Gi1/0/1 and port Te1/0/1

Management VLAN 99 is dedicated for APs and it's different than management VLAN for switches.
I do not utilize wireless mesh.
All APs are Ubiquity brand.

sh span vlan 99

------------------- ---- --- --------- -------- --------------------------------
Gi1/0/2 Desg FWD 4 128.2 P2p
Gi1/0/1 Desg FWD 4 128.3 P2p Edge
Gi1/0/7 Desg FWD 4 128.7 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Te1/0/1 Root FWD 2 128.54 P2p

[paul driver]

Hello

Remove stp portfast off the trunk towards the AP, shutdown/restart the interface and test again.

[berniebbow1]

No change.

---

@paul driver wrote:

Remove stp portfast off the trunk towards the AP, shutdown/restart the interface and test again.

---

[berniebbow1 · Accepted solution]

It's Ubiquiti not Cisco after all.
Disabling Enable connectivity monitor and wireless uplink in site settings in Unifi SDN Controller solves the problem.
More info: https://community.ubnt.com/t5/UniFi-Wireless/Wireless-uplink-causing-network-loop/td-p/2326727