CLI Reference Guide-R04

Chapter 20 | Spanning Tree Commands
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Command Usage
This command sets the maximum time (in seconds) a device can wait without
receiving a configuration message before attempting to reconverge. All device
ports (except for designated ports) should receive configuration messages at
regular intervals. Any port that ages out STA information (provided in the last
configuration message) becomes the designated port for the attached LAN. If it is a
root port, a new root port is selected from among the device ports attached to the
network.
Example
Console(config)#spanning-tree max-age 40
Console(config)#
Related Commands
spanning-tree forward-time (517)
spanning-tree hello-time (518)
spanning-tree mode This command selects the spanning tree mode for this switch. Use the no form to
restore the default.
Syntax
spanning-tree mode {stp | rstp
| mstp}
no spanning-tree mode
stp - Spanning Tree Protocol (IEEE 802.1D)
rstp - Rapid Spanning Tree Protocol (IEEE 802.1w)
mstp - Multiple Spanning Tree (IEEE 802.1s)
Default Setting
rstp
Command Mode
Global Configuration
Command Usage
◆ Spanning Tree Protocol
This option uses RSTP set to STP forced compatibility mode. It uses RSTP for the
internal state machine, but sends only 802.1D BPDUs. This creates one
spanning tree instance for the entire network. If multiple VLANs are
implemented on a network, the path between specific VLAN members may be
inadvertently disabled to prevent network loops, thus isolating group
members. When operating multiple VLANs, we recommend selecting the MSTP
option.