STP parameters and defaults

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

Table 17 Default STP states
Device type	Default STP type	Default STP state	Default STP state of new VLANs¹
Switch image default	STP 802.1d	Enabled	Enabled
Router image default	No span	Enabled	Disabled
Base L3 image default	No span	Disabled	Disabled

^{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. The 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).}

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

Table 18 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.	15 seconds Possible values: 4 - 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 - 40 seconds
Hello Time	The interval of time between each configuration BPDU sent by the root bridge.	2 seconds Possible values: 1 - 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 - 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.

Table 19 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 - 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 Gbps - 4 10 Gbps - 2 Possible values are 0 - 65535

Contents

STP parameters and defaults