Cost to the Root Bridge 10^9/Bandwidth ?

Hi, Just happened on this studying for CIT. Looking at how Root bridges calculate their respective costs using 10^9/Bandwidth. If the BW = 100Mbit/s then the cost = 10 i.e 10^9/100*10^6 = 10. Presumably if using a Gigabit link to root then the cost would be 1. My question is what will happen

Re: Cost to the Root Bridge 10^9/Bandwidth ?

The costs have recently been altered. This is reflected in the Cisco Catalyst switch IOS (except the 1900 series). Link Speed Cost (reratified IEEE spec) Cost (previous IEEE spec) --- 10 Gbps 2

Re: Cost to the Root Bridge 10^9/Bandwidth ?

Cripes !!! Thanx for the reply. So it looks like we have potential "Spanking Tree" problems ahead. We are already rolling with Cat 6000/3500 into our new sites, so any old kit goes in would mean that "spanking Tree" would not be calculated correctly and could go "Loop the Loop". Phil. --