Table of Contents
Which command allows a user to determine the spanning-tree status of a Cisco Catalyst switch for all VLANs?
show spanning-tree vlan command
Use the show spanning-tree vlan command to determine which switch is the root bridge.
What is the difference between Pvst and Pvst+?
Per VLAN Spanning Tree (PVST) is a Cisco proprietary protocol that allows a Cisco device to have multiple spanning trees. PVST+ is an extension of PVST that allows a Cisco device to also interoperate with devices that are running a single spanning tree (IEEE 802.1Q).
What is the command to change the STP mode to Per VLAN spanning-tree?
Step 1 – enabling STP
- switch>enable – It is used to enter privileged mode.
- switch#configure terminal – It is used to enter the switch management interface.
- switch(config)#spanning-tree vlan vlan-id – We use this command to enable the spanning tree protocol on our VLAN.
What is STP Cisco?
The Spanning Tree Protocol (STP) is a network protocol that builds a loop-free logical topology for Ethernet networks. The basic function of STP is to prevent bridge loops and the broadcast radiation that results from them.
What is the show VLAN command?
The show vlans command lists the VLANs currently running in the switch, with VID, VLAN name and VLAN status. Dynamic VLANs appear only if the switch is running with GVRP enabled and one or more ports has dynamically joined an advertised VLAN.
What is difference between Pvst and RSTP?
PVST is usually used on VLANS (or Virtual Local Area Network) while RSTP is often used in LAN. RSTP operates much like STP with Cisco’s enhancements while PVST is a Cisco proprietary in itself. PVST deals with VLANs which means it handles more network devices compared to the RSTP.
How do I configure MSTP?
The overview of configuration is as follows:
- Enable MSTP globally on each switch.
- Configure Switch A, Switch B and Switch C in the same region.
- Configure the priority of Switch B as 4096 to set it as the root bridge in instance 1; configure the priority of Switch C as 4096 to set it as the root bridge in instance 2.
What is Pvst mode in the switch?
With mode ‘pvst’, the switch uses Per-VLAN Spanning-Tree (PVST). Each VLAN runs its own instance of STP using the original 802.1d rules (non-rapid). With mode ‘rapid-pvst’, the switch also uses Per-VLAN Spanning-Tree (PVST). Each VLAN runs its own instance of STP using the updated Rapid STP rules (802.1w).
What is the difference between Pvst and MST?
MST (Multiple Spanning Tree) and PVST+ (Per VLAN Spanning Tree) both offer loop-free layer two topologies but they each use a different approach: MST maps multiple VLANs to an instance, reducing the number of spanning-tree instances. PVST+ calculates an instance for each spanning-tree instance.
What is STP configuration?
The Spanning Tree Protocol (STP) is defined by IEEE standard 802.1D-1988. The STP generates a single spanning tree inside a network. Such mode proved to be useful for supporting applications and protocols in which frames are delivered out of sequence or as duplicates.
How to set root bridge priority in spanning tree?
If an alternate root bridge is desired, use the spanning-tree vlan vlan-id root secondary global configuration mode command. This command sets the priority for the switch to the predefined value 28,672.
Which is the root switch in spanning tree protocol?
The backbone switches often serve as the spanning tree root because these switches typically do not connect to end stations. Also, moves and changes within the network are less likely to affect these switches. After you decide on the root switch, set the appropriate variables to designate the switch as the root switch.
Which is the spanning tree configuration for catalyst 2960?
The default spanning-tree configuration on a Catalyst 2960 Series switch is PVST+. A Catalyst 2960 switch supports PVST+, Rapid PVST+, and MST, but only one version can be active for all VLANs at any time. Example 3-12 displays the commands to configure Rapid PVST+ on S1. Example 3-12 Configuring Rapid PVST+ on S1
Which is the spanning tree global configuration command?
The spanning-tree portfast bpduguard default global configuration command enables BPDU guard on all PortFast-enabled ports. Notice in Example 3-6 how the show running-config interface command can be used to verify that PortFast and BPDU guard have been enabled for a switch port. PortFast and BPDU guard are disabled, by default, on all interfaces.