# TrCRF Spanning Tree Configuration

The Segments Configuration window displays a list of the Token Ring Concentrator Relay Functions (TrCRFs) in the Token Ring Bridge Relay Function (TrBRF) and their spanning-tree configurations.

This window displays the following information:

CRF (dot1dStpPort)

Numeric VTP ID.

State (dot1dStpPortState)

Current status of this TrCRF within the spanning tree. Possible values are disabled, blocked, listening, learning, and forwarding.

Cost (dot1dStpPortPathCost)

Cost associated with the TrCRF. The Spanning-Tree Protocol uses path costs to determine which VLAN to select as a forwarding VLAN. Therefore, lower numbers should be assigned to VLANs that use faster media (such as full-duplex), and higher numbers should be assigned to VLANs that use slower media. The possible range is 1 to 65535. The default is 62. A rule of thumb for the path cost is 1000 / LAN speed, in megabits per second.

Priority (dot1dStpPortPriority)

Priority associated with the TrCRF. The VLAN with the lowest priority value has the highest priority and will forward the spanning-tree frames. The possible range is 0 through 255 (decimal). The default is 128. If all VLANs have the same priority value, the lowest VLAN ID forwards the spanning-tree frames.

To change the path cost and priority of a TrCRF, select the TrCRF and click Apply. Click Cancel to close the dialog box without making any changes. Click Print to print the contents of the dialog box.