Skip to main content
  • Place orders quickly and easily
  • View orders and track your shipping status
  • Enjoy members-only rewards and discounts
  • Create and access a list of your products
  • Manage your Dell EMC sites, products, and product-level contacts using Company Administration.

Force 10 - PVST on Force10 switch blocks untagged VLAN or puts port into err-disable when connected to Cisco or other third party switches

Summary: How to fix err-disable on connection between Force10 and Cisco or other vendor switches.

This article may have been automatically translated. If you have any feedback regarding its quality, please let us know using the form at the bottom of this page.

Article Content


When connecting a Force10 switch running PVST to a Cisco switch the Force10 blocks the untagged VLAN or puts the port into err-disable state. Force10 switches do not allow PVST+ BPDU (tagged or untagged) on an untagged port. If this occurs the switch places the port into an err-disable state or blocks the untagged VLAN.  This could possibly cause the network not to converge.




To prevent this action on the switch you can use the no spanning-tree pvst err-disable cause invalid-pvst-bpdu command from the interface specific configuration mode. After this entry if the port receives a PVST+ BPDU on the untagged VLAN the BPDU is dropped and the port remains operational.


Article Properties

Affected Product

Force10 MXL Blade, Force10 S50-01-GE-48T-V, Force10 S50-01-GE-48T, PowerSwitch S4810P, PowerSwitch S5000, Force10 S50P, Force10 S55T, Force10 S60-44T, PowerSwitch S6000, Dell Networking Z9500

Last Published Date

21 Feb 2021



Article Type