spanning-tree ignore-pvid-inconsistency

Description

Configures port behavior when per-VLAN ID inconsistencies are present. For example, when the ports on both ends of a point-to-point link are untagged members of different VLANs, enabling this option allows RPVST+ to process untagged RPVST+ packets belonging to the peer’s untagged VLAN as if they were received on the current device’s untagged VLAN. When this option is disabled, RPVST+ blocks the link, causing traffic on the mismatched VLANs to be dropped.

If this option is enabled on multiple switches connected by hubs, there could be more than two VLANs involved in PVID mismatches that will be ignored by RPVST+.

If port VLAN memberships is misconfigured on a switch in the network, then enabling this option prevents RPVST+ from detecting the problem, which may result in packet duplication in the network since RPVST+ would not converge correctly.

This command affects all ports on the switch belonging to VLANs on which RPVST+ is enabled.

By default ignore per-VLAN ID inconsistency is disabled.

The no form of this command sets the ignore per-VLAN ID inconsistencies to disabled.

Command context

config

Parameters

enable

Specifies ignore per-VLAN ID inconsistencies and allow RPVST to run on mismatched links.

disable

Disables the ignore per-VLAN ID inconsistencies functionality.

Authority

Administrators

Examples

Enabling ignore per-VLAN ID inconsistencies:

switch# config
switch(config)# spanning-tree ignore-pvid-inconsistency enable

Disabling ignore per-VLAN ID inconsistencies:

switch# config
switch(config)# spanning-tree ignore-pvid-inconsistency disable
switch(config)# no spanning-tree ignore-pvid-inconsistency