54Step Command2. Enter Ethernet interface view or Layer 2 aggregateinterface view. interface interface-type interface-number3. Perform mCheck. stp mcheckNOTE:An mCheck operation takes effect on a router that operates in MSTP or RSTP mode.Configuring the VLAN Ignore featureTraffic of a VLAN on a complex network may be blocked by the spanning tree.Figure 15 VLAN connectivity blocked by MSTPAs shown in Figure 15:• Port A1 on Device A allows the traffic of VLAN 1 to pass through, and Port A2 allows the traffic ofVLAN 2 to pass through.• Port B1 on Device B allows the traffic of VLAN 1 to pass through, and Port B2 allows the traffic ofVLAN 2 to pass through.• Device A and Device B run a spanning tree protocol. Device A is the root bridge, and Port A1 andPort A2 are designated ports. On Device B, Port B1 is the root port, and port B2 is the blocked port.Traffic of VLAN 2 is blocked.• Enabling the VLAN Ignore feature for a VLAN can make ports of the VLAN forward packetsnormally rather than comply with the spanning tree calculation result.Configuring the VLAN Ignore featureTo configure VLAN Ignore:Step Command Remarks1. Enter system view. system-view N/A2. Enable VLAN Ignore for thespecified VLANs. stp ignored vlan vlan-list By default, VLAN Ignore isdisabled.3. Display VLAN Ignore-enabledVLANs.display stp ignored-vlan [ |{ begin | exclude | include }regular-expression ]Optional.Available in any viewVLAN Ignore configuration example1. Network requirements
