Setting Up Spanning Tree Protocol (STP)
All switches from Cisco ship with Spanning Tree Protocol (STP) enabled by default, but if STP is misconfigured for any reason, you can easily enable it. To enable spanning tree, connect to your switch and type spanning-tree mode <selected mode> while in Global Configuration mode.
The following table lists some of the differences among the different versions of spanning tree. The current version of the IOS supports the following modes and defaults to PVST mode.
Switch2> enable
Switch2# configure terminal
Switch2(config)#spanning-tree mode ?
mst Multiple spanning tree mode
pvst Per-Vlan spanning tree mode
rapid-pvst Per-Vlan rapid spanning tree mode
Comparison of STP Versions
| STP Version |
IEEE Identifier |
Failover Interval |
| STP |
802.1D |
30–50 seconds |
| RSTP (Rapid) |
802.1w |
6 seconds (3 Hello intervals) |
| MSTP or MST (Multiple) |
802.1s or 802.1Q-2005 |
6 seconds (3 Hello intervals) |
| PVST (Per VLAN) |
Cisco Proprietary |
6 seconds (3 Hello intervals) |
| R-PVST (Rapid) |
Cisco Proprietary |
6 seconds (3 Hello intervals) |
After you enable a version of STP on your switch, you need to configure some of the options for the STP, with the biggest option being one of the fast technologies. One the most popular of these options is PortFast,.
Switch2> enable
Switch2# configure terminal
Switch2(config)#spanning-tree ?
backbonefast Enable BackboneFast Feature
etherchannel Spanning tree etherchannel specific configuration
extend Spanning Tree 802.1t extensions
loopguard Spanning tree loopguard options
mode Spanning tree operating mode
mst Multiple spanning tree configuration
pathcost Spanning tree pathcost options
portfast Spanning tree portfast options
uplinkfast Enable UplinkFast Feature
vlan VLAN Switch Spanning Tree
Cloud Computing Glossary
cloud computing
A networking solution in which everything — from computing power to computing infrastructure, applications, business processes to personal collaboration — is delivered as a service wherever and whenever you need.
Cloud Computing Glossary
cloud service
The delivery of software, infrastructure, or storage that has been packaged so it can be automated and delivered to customers in a consistent and repeatable manner.
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deprovision
The release of cloud services that are no longer needed.
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federating
Linking distributed resources together over the cloud.
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hypervisor
An operating system that acts as a traffic cop, managing the various virtualization tasks in the cloud to ensure that they make things happen in an orderly manner.
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multi-tenancy
The sharing of underlying resources by multiple companies over a cloud.
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network attached store
Storage that has its own network address through which it is accessed by the network's workstation users. Acronym: NAS
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service level agreement
A contract that stipulates the type of service you need from providers and what type of penalties would result from an unexpected business interruption. Acronym: SLA
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solution stack
An integrated set of software that provides everything a developer needs to build an application.
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storage area network
A storage systems that is flexible and scalable because it's available to multiple hosts at the same time. Acronym: SAN
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vertical industry groups
Workgroups comprised of members from a particular industry such as technology and retail.
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virtual memory
The portion of your hard drive that Windows uses to expand the available RAM
Cloud Computing Glossary
virtualization
Using computer resources to imitate other computer resources or whole computers to maximize performance and flexibility.
