The goal of the question is to enforce where STP is causing ports to put a VLAN into blocking mode. This requires working with the root location and port costs. Since the root location is already set, we need to use cost.
The wording of the questions isn't that clear. But I guess based on the solution text, let's make the goal to block the Cat1-Cat2 link for odd VLANs and block the Cat2-Cat3 link for the even VLANs. A key point to keep in mind is that when setting the cost on a port, that is the cost that is added to the BDPU when receiving the BPDU into the port. It does not have any impact on BPDUs sent out of the port. Cat1 is the root for odd VLANs and Cat2 is the root for even VLANs. So at default port priorities, cat3 is blocking odd VLANs on its uplink to Cat2 and blocking even VLANs on its uplink to Cat1. Cat1 and Cat2 are not blocking anything. You can see this in the "show spanning-tree" command. The quick way to look for what is blocking would be to use "sho spann | in VLAN|BLK" When we apply the "spanning-tree vlan 5,11,13,15,17,105,111,113,131 cost 39" command to Po1 on Cat2, we then see the odd VLANs being blocked on Cat2's Po1 interface. That will cause traffic on these VLANs from Cat1 to traverse Cat3 to get to Cat2. If we try to follow the solutions guide for switch 3, it applies the cost for the ven VLANs to port fa0/22, which is already blocking the even VLANs. After applying this, nothing changes in terms of what links are blocking. But if we apply it to port fa0/20, then the even VLANs start blocking on the Cat2-Cat3 link and we meet the desired requirements. So you are correct that it needs to be applied to the fa0/20 interface. Jeff Rensink - CCIE #24834 (Wireless, R&S) Senior Technical Instructor - IPexpert On Thu, Feb 21, 2013 at 11:30 AM, Brian Stamper <[email protected]>wrote: > Can someone from IP Expert verify the initial possible error here? > > > On Sat, Feb 16, 2013 at 7:56 AM, Brian Stamper <[email protected]>wrote: > >> Hey Kyle, >> Hows it going! This is why I'm trying to be more detailed with things. >> My biggest issue seems to be comprehension of the requirements in the >> question. I haven't ever read between the lines well or found a needle in >> a haystack and it appears to me many of the questions are like that. The >> instructor for the bootcamp I went to explained it as "The questions have >> depth to them". So learning to pick out what is being asked is my >> biggest challenge. Some of these errors in the workbook are actually good >> for me compiled with my lab not being identical to the IPExpert topology. >> Taking the time to understand the technology and having to "migrate" the >> solution into my lab seems to be a big help. The only issue is is making >> sure I have support to clarify the errors when I find them as without that >> I start to second guess myself. >> Thanks, >> Brian >> >> >> On Sat, Feb 16, 2013 at 7:14 AM, Brian Stamper >> <[email protected]>wrote: >> >>> Its in the workbook and from what I've heard there is quite a bit of >>> route/switch with basic Routing with protocols/static routes, QOS, Spanning >>> Tree, port security, Multicast, etc. I am just asking for clarification on >>> this particular Lab 1.3 that appears to have an error. Hopefully one of >>> the IPExpert people can clarify. >>> >>> >>> On Sat, Feb 16, 2013 at 2:50 AM, Stefan Angerer >>> <[email protected]>wrote: >>> >>>> Yes …**** >>>> >>>> ** ** >>>> >>>> Regards**** >>>> >>>> Stefan**** >>>> >>>> ** ** >>>> >>>> *Von:* [email protected] [mailto: >>>> [email protected]] *Im Auftrag von *alan blake >>>> *Gesendet:* Samstag, 16. Februar 2013 09:39 >>>> *An:* Brian Stamper >>>> *Cc:* [email protected] >>>> *Betreff:* Re: [OSL | CCIE_Wireless] IPExpert Lab 1.3**** >>>> >>>> ** ** >>>> >>>> Should the level of trouble shooting be geared around wireless >>>> misconfiguration rather than r&s? Is this common to the lab to troubleshoot >>>> spanning tree in this detail? **** >>>> >>>> On 15 Feb 2013 22:13, "Brian Stamper" <[email protected]> wrote:* >>>> *** >>>> >>>> I think I found an error in this Lab. **** >>>> >>>> I believe the cost for the even vlans is applied to the wrong >>>> interface. In order to make Cat3 prefer a route through Cat1 to the root >>>> Cat2 for even vlans we'd have to apply the cost to Fa 0/20 on Cat3. The >>>> workbook and final configs have it on Fa0/22 on cat 3 (pointing the wrong >>>> way). The cost on the path out of Fa0/22 for the even vlans is already 31 >>>> where the cost out Fa0/20 is 19 as its directly connected. We would need >>>> to raise it on Fa0/20 to 32 and not on Fa0/22. Is there someone who can >>>> confirm this for me. >>>> -- **** >>>> >>>> Thanks,**** >>>> >>>> Brian Stamper CCNP Wireless, VCP**** >>>> >>>> 5157243424**** >>>> >>>> ** ** >>>> >>>> >>>> _______________________________________________ >>>> 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**** >>>> >>>> >>> >>> >>> -- >>> Thanks, >>> Brian Stamper CCNP Wireless, VCP >>> 5157243424 >>> >>> >> >> >> -- >> Thanks, >> Brian Stamper CCNP Wireless, VCP >> 5157243424 >> >> > > > -- > Thanks, > Brian Stamper CCNP Wireless, VCP > 5157243424 > > > _______________________________________________ > 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 > >
_______________________________________________ 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
