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 difference between 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.
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 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 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 and BackboneFast?
btw the basic difference is that uplinkfast only allows quick failover of connected links (ie. blocked ports) whereas backbonefast removes the can detect topology changes due to indirect link failures.
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 UplinkFast and Backbonefast?
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.
Why PortFast is used?
The mode of the port changes from PortFast to non-PortFast when the port receives a STP BPDU. To re-enable this feature on a port, run the shut command followed by a no-shut command at the interface/port level. Configuring PortFast on a non-edge port can cause instability to the STP topology.
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.
What is 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.
What is uplinkfast on a Cisco switch?
The UplinkFast feature is designed to run in a switched environment when the switch has at least one alternate/backup root port (port in blocking state), that is why Cisco recommends that UplinkFast be enabled only for switches with blocked ports, typically at the access-layer.
How does uplinkfast work in STP?
UplinkFast optimizes convergence when an uplink fails on an access layer switch. For good STP design, access layer switches should not become root or become transit switches. (A transit switch is a switch that forwards frames between other switches.)
What is the difference between spanning tree and uplinkfast?
By default, spanning tree sends BPDUs from all ports regardless of whether PortFast is enabled. BDPU filtering is on a per-switch basis; after you enable BPDU filtering, it applies to all PortFast-enabled ports on the switch. UplinkFast provides fast convergence using uplink groups in the network access layer after a spanning tree topology change.
