Brocade Mobility RFS Controller System Reference Guide (Supporting software release 5.5.0.0 and later) - Manual (Page 122)

110 Brocade Mobility RFS Controller System Reference Guide
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20. Refer to the Spanning Tree Port Cost table.
Define or override an Instance Index using the spinner control and then set the Cost. The
default path cost depends on the user defined port speed. The cost helps determine the role of
the port channel in the MSTP network.
The designated cost is the cost for a packet to travel from this port to the root in the MSTP
configuration. The slower the media, the higher the cost.
21. Refer to the Spanning Tree Port Priority table.
Define or override an Instance Index using the spinner control, then set the Priority. The
lower the priority, the greater likelihood of the port becoming a designated port.
22. Select + Add Row as needed to include additional indexes.
23. Select OK to save the changes and overrides made to the Ethernet Port Spanning Tree
configuration. Select Reset to revert to the last saved configuration.
VM Interface Override Configuration
Profile Interface Override Configuration
Link Type Select either the Point-to-Point or Shared radio button. Selecting Point-to-Point indicates the port
should be treated as connected to a point-to-point link. Selecting Shared indicates this port should be
treated as having a shared connection. A port connected to a hub is on a shared link, while one
connected to a controller or service platform is a point-to-point link. Point-to-Point is the default
setting.
Cisco MSTP
Interoperability Select either the Enable or Disable radio buttons. This enables interoperability with Cisco’s version of
MSTP, which is incompatible with standard MSTP. This setting is disabled by default.
Force Protocol Version Sets the protocol version to either STP(0), Not Supported(1), RSTP(2) or MSTP(3). MSTP is the default
setting.
Guard Determines whether the port channel enforces root bridge placement. Setting the guard to Root
ensures the port is a designated port. Typically, each guard root port is a designated port, unless two
or more ports (within the root bridge) are connected together. If the bridge receives superior (BPDUs)
on a guard root-enabled port, the guard root moves the port to a root-inconsistent STP state. This
state is equivalent to a listening state. No data is forwarded across the port. Thus, the guard root
enforces the root bridge position.
Speed Default Path Cost
<=100000 bits/sec 200000000
<=1000000 bits/sec 20000000
<=10000000 bits/sec 2000000
<=100000000 bits/sec 200000
<=1000000000 bits/sec 20000
<=10000000000 bits/sec 2000
<=100000000000 bits/sec 200
<=1000000000000 bits/sec 20
>1000000000000 bits/sec 2