Cisco Catalyst - %SPANTREE-7-RECV_1Q_NON_TRUNK.

Today I faced some new issue for me. Of course it’s all about wrong configuration, but this is interesting one. So, after connection access switch to uplink toward distribution layer switch, port LED went to green and after a second to amber state.

I went to see the logs:

*Mar  1 00:26:07.193: %SPANTREE-7-RECV_1Q_NON_TRUNK: Received 802.1Q BPDU on non trunk FastEthernet0/48 VLAN1.
*Mar  1 00:26:07.193: %SPANTREE-7-BLOCK_PORT_TYPE: Blocking FastEthernet0/48 on VLAN0001. Inconsistent port type.

The switches have the following configs:

interface Gi0/1
 description To Access Switch
 switchport mode access
 switchport voice vlan 100
 spanning-tree portfast
interface FastEthernet0/48
 description To Upper Switch
 switchport mode access
 spanning-tree portfast

There are so many solutions:

• Disable STP on Access switch for the particular VLAN.
• Disable Voice VLAN on Distribution switch side.
• Remove “spanning-tree portfast” statements.

I’ve also found this interesting post about the same problem.

All in all, it’s all about wrong network planning or configuration…

Admin area