What is Spanning Tree UplinkFast?

UplinkFast is a Cisco specific feature that improves the convergence time of the Spanning-Tree Protocol (STP) in the event of the failure of an uplink. The UplinkFast feature is supported on Cisco Catalyst 4500/4000, 5500/5000, and 6500/6000 series switches running CatOS.

How does rapid spanning tree work?

Rapid Spanning Tree Protocol (RSTP) is a network protocol that ensures a loop-free topology for Ethernet networks. RSTP defines three port states: discarding, learning, and forwarding and five port roles: root, designated, alternate, backup, and disabled.

What is Portfast UplinkFast and BackboneFast?

UplinkFast, Backbone Fast and Portfast are Cisco’s proprietary extensions to the Classic Spanning Tree Protocol (STP 802.1 D) algorithm. The purpose UplinkFast, Backbone Fast and Portfast are to reduce the time it takes Spanning Tree Protocol (STP) to converge after a link failure.

What it is the convergence time in STP in case of direct link failure if UplinkFast enable?

Here’s the big difference. When uplinkfast is enabled a non-designated port will go to forwarding state immediately if the root port fails. Instead of 30 seconds downtime connectivity is restored immediately.

What is the purpose of UplinkFast?

The purpose UplinkFast, Backbone Fast and Portfast are to reduce the time it takes for classic Spanning Tree Protocol (STP) to converge after a link failure. UplinkFast extension is useful for Direct Link failures (a link connected directlly to the same Switch).

What is the difference between UplinkFast and PortFast?

PortFast BPDU filtering allows access ports to move directly to the forwarding state as soon as the end hosts are connected. UplinkFast provides fast convergence after a direct link failure and achieves load balancing between redundant Layer 2 links using uplink groups.

What is the difference between Spanning Tree and Rapid Spanning Tree?

The main difference between Rapid Spanning Tree Protocol (RSTP IEEE 802.1W) and Spanning Tree Protocol (STP IEEE 802.1D) is that Rapid Spanning Tree Protocol (RSTP IEEE 802.1W) assumes the three Spanning Tree Protocol (STP) ports states Listening, Blocking, and Disabled are same (these states do not forward Ethernet …

Is STP better than RSTP?

Rapid spanning tree protocol (RSTP) is as its name suggests, a faster transition to a port-forwarding state. Unlike STP, which has five switchport states, RSTP has only three: discarding, learning, and forwarding.

What is STP BackboneFast?

The BackboneFast extension can dramatically decrease the convergence time of the Spanning Tree Protocol (STP) in the event of an Indirect link (a link in any other switch, which is not connected directly) failure, anywhere in the Spanning Tree Protocol (STP) Topology. The link between Switch omnisecu.com.

How do I enable loop guard?

Issue this command in order to enable loop guard globally:

1. CatOS Console> (enable) set spantree global-default loopguard enable.
2. Cisco IOS Router(config)#spanning-tree loopguard default.

How long does it take for spanning tree to converge?

If a port has to go through all four states, convergence takes 50 seconds: 20 seconds in blocking, 15 seconds in listening, and 15 seconds in learning. If a port doesn’t have to go through the blocking state but starts at a listening state, convergence takes only 30 seconds.

What is Spanning Tree Protocol ( STP ) uplinkfast?

The UplinkFast extension can dramatically decrease the convergence time of the Spanning Tree Protocol (STP) in the event of the Direct link (a link connected directlly to the same Switch) failure of an uplink on an Access Layer switch.

What is the purpose of uplinkfast, backbone fast and portfast?

The purpose UplinkFast, Backbone Fast and Portfast are to reduce the time it takes Spanning Tree Protocol (STP) to converge after a link failure. Features similar to UplinkFast, Backbone Fast and Portfast are built into Rapid Spanning Tree Protocol (RSTP) .

How long does it take to recover from uplinkfast?

With the default STP parameters, the recovery takes up to 30 seconds, and with aggressive timer tuning, this lapse of time can be reduced to 14 seconds. The UplinkFast feature is a Cisco proprietary technique that reduces the recovery time further down to the order of one second.

When was the Rapid Spanning Tree Protocol ( RSTP ) introduced?

IEEE Standards. Rapid Spanning Tree Protocol (RSTP) – First introduced in 1982 as an evolution of STP (802.1D standard). It provides faster spanning-tree convergence after a topology change. RSTP implements the Cisco-proprietary STP extensions, BackboneFast, UplinkFast, and PortFast, into the public standard.