VLAN changing

[geocoles]

I have a strange one. C9200 switch, 17.03.04b. Setting up a port for a postage machine. config as follows:

ip dhcp pool cin-6
address 10.3.6.2 client-id 0100.1b00.4116.4d

interface GigabitEthernet1/0/15
description Postage machine
switchport access vlan 6
switchport mode access
speed 100
duplex full
no cdp enable
spanning-tree portfast
spanning-tree bpdufilter enable
spanning-tree bpduguard enable
end

If I view the port(sh run) before the device is brought online I see it in VLAN 6, as expected.

But once the device comes online, the VLAN changes to VLAN 20. The config of the device is very simple, either DHCP or static. It is set for DHCP. 

Don't understand why it changes VLANs, any ideas?

[Richard Burts]

Are there any log messages generated when the device is brought on line? If so please post them.

Would you post the output of show interface status after configuration and before bringing the device on line, bring the device on line and post the output of show interface status when machine is on line.

[paul driver]

Hello

---

@geocoles wrote:
But once the device comes online, the VLAN changes to VLAN 20. The config of the device is very simple, either DHCP or static. It is set for DHCP.
Don't understand why it changes VLANs, any ideas?

---

Seems strange -

Have you tried defaulting the port and reconfiguring also not enable bpdufilter

conf t
default interface GigabitEthernet1/0/15
interface GigabitEthernet1/0/15
description Postage machine
switchport host
switchport access vlan 6
speed 100
duplex full
spanning-tree portfast
spanning-tree bpduguard enable

[MHM Cisco World]

change of VLAN from

1- 802.1x which you dont use

2- macro or EEM <<- this can also change VLAN 

if not point 2 

are vlan 20 is native vlan ?

MHM