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The "%SPANTREE-7-BLOCK_PORT_TYPE : Blocking [chars] on [chars]. Inconsistent port type" message is logged on Cisco Catalyst switches

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Core issue

The error message is due to the specified interface that has an inconsistent port type and is being held in a spanning-tree blocking state until the port type inconsistency is resolved.

Resolution

Whenever the %SPANTREE-7-BLOCK_PORT_TYPE : Blocking [chars] on [chars]. Inconsistent port type message is received in the logs, perform this procedure:

  1. Issue the show interfaces fastethernet switchport command on the listed interface and on the  interface to which it is connected, to verify they have the same mode (access or trunk).
  2. If the mode is trunk, verify that both interfaces use the same  encapsulation (ISL or 802.1Q).
  3. Issue the show spanning-tree command for these particular ports, to verify they both are in forwarding mode.

Note: When these parameters are consistent, spanning tree automatically  unblocks the interfaces, and the message can be ignored. To avoid these messages in the logs, the logging level must be set to higher than debugging. 

Comments
eclinton
Beginner

I ran into this issue when cabling 2 switches together because 1 of the switchports was configured with an access vlan and a voice vlan. I removed the voice vlan from the switchport so it was only config'd with an access vlan and then port inconsistant status cleared. 

eng.ahmed.fakhry
Beginner

Eclinton,

 

Thanks a lot , after more than an hour troubleshooting ,yours were the solution

 

Just removed the voice vlan and it works :)

theovicel1
Beginner

Hi, 

thanks for sharing, i run the same issue. Despite the fact that interfaces was both on access mode.

To solve it i used no spanning-tree vlan "vlan ID".