Hello George, diameter is just a parameter for the macro that is triggered by the command 'spanning-tree vlan x root primary diameter n'. This parameter will make some adjustments to the STP timers. Marko has a good post about this topic:
http://blog.ipexpert.com/2011/01/24/old-ccie-myths-spanning-tree-diameter/ Regards. On Thu, Aug 8, 2013 at 8:59 PM, George Leslie <[email protected]>wrote: > Hi List! > Another one that's caused me some confusion over the years! > > In the macro: > > spanning-tree vlan x root primary diameter y > > what exactly is the diameter? > > I've got my copy of Clark/Hamilton here, and they define it as: > > "the maximum number of bridges that any two end work stations have to go > through to communicate". > > That is all well and good, but on what basis? Is that on the basis of a > network that is fully functional, where STP is stable and all links are > functional? Or do you take a conservative, worst case scenario, in which > there have been link failures and the longest possible string of switches > exist? > > E.G in the proctor labs set up, with all inter-switch links configured, > you'd have a diameter of 2 as every switch is directly connected to the > root switch. OR....do you say that if there are link failures, a frame may > have to go through 4 switches to reach its destination? > > Or say that only the outside links are up (the diagonals of the square are > shut). That would give a diameter of 3 if taking steady state into > account, or 4 if you are catering for link failure. > > In an exam, which do you choose? > > George. > > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com > > http://onlinestudylist.com/mailman/listinfo/ccie_rs > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
