Administrator Guide

This feature is the same as PortFast mode in spanning tree.
CAUTION: Congure EdgePort only on links connecting to an end station. EdgePort can cause loops if you enable it on an
interface connected to a network.
To enable EdgePort on an interface, use the following command.
• Enable EdgePort on an interface.
INTERFACE mode
spanning-tree pvst edge-port [bpduguard | shutdown-on-violation]
The EdgePort status of each interface is given in the output of the show spanning-tree pvst command, as previously shown.
Dell Networking OS Behavior: Regarding the bpduguard shutdown-on-violation command behavior:
• If the interface to be shut down is a port channel, all the member ports are disabled in the hardware.
• When you add a physical port to a port channel already in an Error Disable state, the new member port is also disabled in the hardware.
• When you remove a physical port from a port channel in an Error Disable state, the Error Disabled state is cleared on this physical port
(the physical port is enabled in the hardware).
• The reset linecard command does not clear the Error Disabled state of the port or the hardware Disabled state. The interface
continues to be disables in the hardware.
• You can clear the Error Disabled state with any of the following methods:
• Perform a shutdown command on the interface.
• Disable the shutdown-on-violation command on the interface (the no spanning-tree stp-id portfast
[bpduguard | [shutdown-on-violation]] command).
• Disable spanning tree on the interface (the no spanning-tree command in INTERFACE mode).
• Disabling global spanning tree (the no spanning-tree command in CONFIGURATION mode).
PVST+ in Multi-Vendor Networks
Some non-Dell Networking systems which have hybrid ports participating in PVST+ transmit two kinds of BPDUs: an 802.1D BPDU and an
untagged PVST+ BPDU.
Dell Networking systems do not expect PVST+ BPDU (tagged or untagged) on an untagged port. If this situation occurs, the system
places the port in an Error-Disable state. This behavior might result in the network not converging. To prevent the system from executing
this action, use the no spanning-tree pvst err-disable cause invalid-pvst-bpdu command. After you congure this
command, if the port receives a PVST+ BPDU, the BPDU is dropped and the port remains operational.
Enabling PVST+ Extend System ID
In the following example, ports P1 and P2 are untagged members of dierent VLANs. These ports are untagged because the hub is VLAN
unaware. There is no data loop in this scenario; however, you can employ PVST+ to avoid potential miscongurations.
If you enable PVST+ on the Dell Networking switch in this network, P1 and P2 receive BPDUs from each other. Ordinarily, the Bridge ID in
the frame matches the Root ID, a loop is detected, and the rules of convergence require that P2 move to blocking state because it has the
lowest port ID.
To keep both ports in a Forwarding state, use extend system ID. Extend system ID augments the bridge ID with a VLAN ID to dierentiate
BPDUs on each VLAN so that PVST+ does not detect a loop and both ports can remain in a Forwarding state.
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Per-VLAN Spanning Tree Plus (PVST+)