What is PortFast UplinkFast and BackboneFast?
What is PortFast UplinkFast and BackboneFast?
UplinkFast works by finding alternate ports for directly connected links. Similarly BackboneFast works on finding an alternate path when an indirect link to the root port goes down. SwitchA is the Root Bridge here and Fa0/20 on SwitchD in the root port.
What is the difference between UplinkFast and PortFast?
Portfast facilitate the laptop computer to be online going past the listening & learning state of switch port . Switch(config-if)# switchport host. UplinkFast: An access-layer switch which has redundant uplink connections to 2 distribution-layer switches .
What is UplinkFast in switch?
UplinkFast provides the immediate shift to alternate port by determining the possible paths going to the Root Switch (Root Bridge). The collection of possible paths going to the Root Switch (Root Bridge) are called uplink group.
What does enabling PortFast on a Switchport do?
Enabling the PortFast feature causes a switch or a trunk port to enter the STP forwarding-state immediately or upon a linkup event, thus bypassing the listening and learning states. The PortFast feature is enabled at a port level, and this port can either be a physical or a logical port.
What is UplinkFast in Cisco?
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. Do not use on switches without the implied topology knowledge of a alternative/backup root link typically to distribution and core switches in Cisco multilayer design.
What is UplinkFast?
Uplinkfast is a spanning-tree feature that was created to improve the convergence time. In this lesson we’ll take a look at how uplinkfast works. Here’s the topology that I will use to demonstrate it: Three switches and SW1 is our root bridge. The fa0/16 interface on SW3 has been blocked.
What is Backbonefast?
Backbone Fast is used to recover from an indirect link failure.
Should you use PortFast?
PortFast feature should be used only to connect a single workstation to a switch port to avoid layer 2 switching loop. Spanning Tree PortFast feature causes a port to enter the forwarding state immediately, bypassing the listening and learning states.
How do I enable UplinkFast?
To enable UplinkFast on a VLAN with switch priority configured, first restore the switch priority on the VLAN to the default value by using the no spanning-tree vlan vlan-id priority global configuration command. UplinkFast on an individual VLAN. The UplinkFast feature is supported only when the switch is running PVST.
What is switch port Fast?
Switch ports are Layer 2-only interfaces associated with a physical port. A switch port can be an access port, a trunk port, or a tunnel port….Tunnel Ports.
| Command | Purpose |
|---|---|
| 3550(config-if)# switchport access vlan vlan-id | Assign the port to a VLAN. Valid VLAN IDs are 1 to 4094; do not enter leading zeros. |
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.
What is the purpose of uplinkfast, backbone fast and portfast?
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.
When do I need to enable uplinkfast on my Cisco switch?
Note: UplinkFast only works when the switch has blocked ports. The feature is typically designed for an access switch that has redundant blocked uplinks. When you enable UplinkFast, it is enabled for the entire switch and cannot be enabled for individual VLANs.
What happens when portfast is enabled on a switch?
In effect, convergence happens instantly on ports with PortFast enabled. Of course, if another switch is connected to a port on which PortFast is enabled, loops may occur. So, PortFast is intended for access links attached to single end-user devices.
What is the uplinkfast feature on Cisco Catalyst 5500?
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.
