What is path cost?
What is path cost?
Path cost – The path cost is the metric stp uses to calculate the shortest path to elect root port to reach the root-bridge . The path cost is based on the speed of the interface of switch .
How does STP path change cost?
By changing the STP port costs with the command spanning tree [vlan vlan-id] cost cost, you can modify the STP forwarding path. You can lower a path that is currently an alternate port while making it designated, or you can raise the cost on a port that is designated to turn it into a blocking port.
Why is it a best practice to manually select the root bridge?
Overview. Confirming the correct root bridge election in a switched network is important for increasing the stability of a switched network. The root bridge is selected by manually configuring its bridge priority to a low value. 32768 is the default value out of a range from 0 to 61440.
How do I choose a root bridge?
The root bridge is selected by manually configuring its bridge priority to a low value. 32768 is the default value out of a range from 0 to 61440. If all switches in a single spanning tree have the same bridge priority, the switch with the lowest MAC address will become the root bridge.
How do you make a root bridge?
To configure a Switch to become the Spanning Tree Protocol (STP) Root Bridge (Root Switch) for a VLAN, you can use the “spanning-tree vlan root” command from the Global Configuration Mode.
How is spanning tree path cost value calculated?
Spanning Tree Path Cost Value and How is Spanning Tree Path Cost Value Calculated Link Speed Cost Value 10 Gbps 2 1 Gbps 4 100 Mbps 19 10 Mbps 100
What do I need to run cost path?
One or more of the weighted cost tools ( Cost Distance, Cost Back Link, or Cost Allocation) are generally required to run prior to running Cost Path to create the input cost distance and back link rasters. These are mandatory input rasters to Cost Path. Each least-cost path is assigned a value when encountered in the scanning process.
How is the path cost calculated in STP?
The path cost is the metric STP uses to calculate the shortest path to the elected root bridge. The path cost is based on the speed of the bridge port interface. Back when Radia Perlman developed the Spanning Tree Protocol, 10 GE links were not even considered within the realm of possibility.
How does the cost path tool work in Excel?
The Cost Path tool produces an output raster that records the least-cost path or paths from selected locations to the closest source cell defined within the accumulative cost surface, in terms of cost distance.