STP Parameters and Defaults

The following table lists the default STP states for RUCKUS devices.

Default STP States

Device Type Default STP Type Default STP State Default STP State of New VLANs1
Router image default STP 802.1D Enabled Disabled

The following table lists the default STP bridge parameters. The bridge parameters affect the entire spanning tree. If you are using Multiple Spanning Tree Protocol (MSTP), the parameters affect the VLAN. If you are using Single Spanning Tree Protocol (SSTP), the parameters affect all VLANs that are members of the single spanning tree.

Default STP Bridge Parameters

Parameter Description Default and Valid Values
Forward Delay

The period of time spent by a port in the listening and learning state before moving on to the learning or forwarding state, respectively.

The forward delay value is also used for the age time of dynamic entries in the filtering database, when a topology change occurs.

5 seconds

Possible values: 4 through 30 seconds

Maximum Age

The interval a bridge will wait for a configuration BPDU from the root bridge before initiating a topology change.

20 seconds

Possible values: 6 through 40 seconds

Hello Time

The interval of time between each configuration BPDU sent by the root bridge.

2 seconds

Possible values: 1 through 10 seconds

Priority

A parameter used to identify the root bridge in a spanning tree (instance of STP). The bridge with the lowest value has the highest priority and is the root.

A higher numerical value means a lower priority; thus, the highest priority is 0.

32768

Possible values: 0 through 65535

Note: If you plan to change STP bridge timers, RUCKUS recommends that you stay within the following ranges, from section 8.10.2 of the IEEE STP specification. 2 * (forward_delay -1) >= max_agemax_age >= 2 * (hello_time +1)

The following table lists the default STP port parameters. The port parameters affect individual ports and are separately configurable on each port.

Default STP Port Parameters

Parameter Description Default and Valid Values
Priority

The preference that STP gives this port relative to other ports for forwarding traffic out of the spanning tree.

A higher numerical value means a lower priority.

128

Possible values: 0 through 240 (configurable in increments of 16)

Path Cost The cost of using the port to reach the root bridge. When selecting among multiple links to the root bridge, STP chooses the link with the lowest path cost and blocks the other paths. Each port type has its own default STP path cost.

10 Mbps: 100

100 Mbps: 19

1 Gbps: 4

10 Gbps: 2

Possible values: 0 through 65535

  1. When you create a port-based VLAN, the new VLAN STP state is the same as the default STP state on the device. The new VLAN does not inherit the STP state of the default VLAN. Single Spanning Tree Protocol (SSTP) is another type of STP. SSTP includes all VLANs on which STP is enabled in a single spanning tree. Refer to Single Spanning Tree (SSTP) ↩
Parent topic: Standard STP Parameter Configuration