Dell BigIron RX Series, Configuration Manual

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340 BigIron RX Series Configuration Guide
53-1002253-01
IEEE Single Spanning Tree (SSTP)
12
TABLE 76 CLI display of STP information for the specified Ethernet interface
IEEE Single Spanning Tree (SSTP)
By default, each port-based VLAN on the device runs a separate spanning tree, which you can
enable or disable on an individual VLAN basis.
Alternatively, you can configure the device to run a single spanning tree across all of its ports and
VLANs. The SSTP feature is especially useful for connecting a device to third-party devices that run
a single spanning tree in accordance with the 802.1q specification.
This field... Displays...
<slot/port>
The STP/RSTP/MSTP protocol information for the specified ethernet
interface.
NOTE: If the Ethernet interface is not added to any STP enabled VLANs,
the command displays the following message instead: "No
STP-configured VLANs for the port <slot/port>”.
STP port parameters
Port Num The port number.
Priority NOTE: If you configure this value, specify it in decimal format. Refer to
“Changing STP port parameters” on page 330.
Path Cost The port’s STP path cost.
State The port’s STP state. The state can be one of the following:
•
BLOCKING – STP has blocked Layer 2 traffic on this port to prevent
a loop. The device or VLAN can reach the root bridge using another
port, whose state is FORWARDING. When a port is in this state, the
port does not transmit or receive user frames, but the port does
continue to receive STP BPDUs.
•
DISABLED – The port is not participating in STP. This can occur
when the port is disconnected or STP is disabled on the port.
•
FORWARDING – STP is allowing the port to send and receive
frames.
•
LISTENING – STP is responding to a topology change and this port
is listening for a BPDU from neighboring bridges in order to
determine the new topology. No user frames are transmitted or
received during this state.
•
LEARNING – The port has passed through the LISTENING state and
will change to the BLOCKING or FORWARDING state, depending on
the results of STP’s reconvergence. The port does not transmit or
receive user frames during this state. However, the device can
learn the MAC addresses of frames that the port receives during
this state and make corresponding entries in the MAC table.
Designated Cost The cost to the root bridge as advertised by the designated bridge that is
connected to this port. If the designated bridge is the root bridge itself,
then the cost is 0. The identity of the designated bridge is shown in the
Design Bridge field.
Designated Root The root bridge as recognized on this port. The value is the same as the
root bridge ID listed in the Root ID field.
Designated Bridge The bridge as recognized on this port.