H3C Technologies H3C S5120 Series Switches - Manual (Page 195)

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To do... Use the command... Remarks
Enter system view system-view —
Enter Layer 2 Ethernet port view, or
Layer 2 aggregate port view interface interface-type
interface-number
—
Perform mCheck stp mcheck Required
An mCheck operation takes effect on a device only when MSTP operates in RSTP or MSTP mode.
Configuring the VLAN Ignore Feature
Traffic on a VLAN in a complex network may be blocked by the spanning tree.
Figure 1-6 VLAN connectivity blocked by MSTP
As shown above, port A on Device A allows the traffic of VLAN 1 to pass through, and port C allows the
traffic of VLAN2 to pass through; port B on Device B allows the traffic of VLAN 1 to pass through, and
port D allows the traffic of VLAN 2 to pass through. Device A and Device B run MSTP, Device A is the
root bridge, and port A and port C on it are designated ports. Port B on Device B is the root port, and port
D is the blocked port. Traffic on VLAN 2 is blocked.
Enabling the VLAN Ignore feature for a VLAN can make ports of the VLAN forward packets normally
rather than comply with the calculated result of MSTP.
Configuration Procedure
Follow these steps to configure VLAN Ignore:
To do... Use the command... Remarks
Enter system view system-view —
Enable VLAN Ignore for the
specified VLAN(s)
stp ignored vlan vlan-list Required
Display VLAN Ignore enabled
VLANs
display stp ignored-vlan Available in any view
Configuration Example
Network requirements
z
Device A and Device B are directly connected;