Indeed, thanks for the help On Thu, Jun 10, 2010 at 10:28 AM, Tyson Scott <[email protected]> wrote:
> As long as it works that is the important thing right ;) > > > > Regards, > > > > Tyson Scott - CCIE #13513 R&S, Security, and SP > > Managing Partner / Sr. Instructor - IPexpert, Inc. > > Mailto: [email protected] > > Telephone: +1.810.326.1444, ext. 208 > > Live Assistance, Please visit: www.ipexpert.com/chat > > eFax: +1.810.454.0130 > > > > IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, > Audio Tools, Online Hardware Rental and Classroom Training for the Cisco > CCIE (R&S, Voice, Security & Service Provider) certification(s) with > training locations throughout the United States, Europe, South Asia and > Australia. Be sure to visit our online communities at > www.ipexpert.com/communities and our public website at www.ipexpert.com > > > > *From:* Joshua Yost [mailto:[email protected]] > *Sent:* Thursday, June 10, 2010 10:59 AM > > *To:* Tyson Scott > *Cc:* ccie_rs > *Subject:* Re: [OSL | CCIE_RS] Sham WOW part 2 > > > > Thanks for clarifying. And again I agree for resiliency we should have the > VL on both sides - but for instance, if you were using IP unnumbered on the > backdoor link, you'd be unable to extend a virtual link from the area > 222/area 0 ABR to the PE router on the area 222 side of things. > > > > On Thu, Jun 10, 2010 at 9:53 AM, Tyson Scott <[email protected]> wrote: > > As far as operation is considered as long Area 0 is continuous with Area > 111 in tact the sham link will function. It doesn't have to touch area 0 on > both sides to function. You should implement it to prevent a failure. > > > > Regards, > > > > Tyson Scott - CCIE #13513 R&S, Security, and SP > > Managing Partner / Sr. Instructor - IPexpert, Inc. > > Mailto: [email protected] > > Telephone: +1.810.326.1444, ext. 208 > > Live Assistance, Please visit: www.ipexpert.com/chat > > eFax: +1.810.454.0130 > > > > IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, > Audio Tools, Online Hardware Rental and Classroom Training for the Cisco > CCIE (R&S, Voice, Security & Service Provider) certification(s) with > training locations throughout the United States, Europe, South Asia and > Australia. Be sure to visit our online communities at > www.ipexpert.com/communities and our public website at www.ipexpert.com > > > > *From:* Joshua Yost [mailto:[email protected]] > > *Sent:* Thursday, June 10, 2010 10:50 AM > *To:* Tyson Scott > > *Cc:* ccie_rs > > > *Subject:* Re: [OSL | CCIE_RS] Sham WOW part 2 > > > > Where is the discontinuous area 0? Area 0 extends through area 111 with a > virtual link, then the sham link goes over MPLS in area 0. > > There are scenarios where a virtual link on the area 222 side of things may > be impossible. > > What I am confused about is, in what capacity is the sham link in area 0 > functioning if there is no area 0 on the other side of it? From my testing, > it is certainly doing something, but this goes against the "requirement" > that the sham link be connecting a single area. > > On Thu, Jun 10, 2010 at 9:39 AM, Tyson Scott <[email protected]> wrote: > > The reason you should want Area0 on both sides is for fault tolerance. If > you use one you will have discontiguous area 0's. > > > > Regards, > > > > Tyson Scott - CCIE #13513 R&S, Security, and SP > > Managing Partner / Sr. Instructor - IPexpert, Inc. > > Mailto: [email protected] > > Telephone: +1.810.326.1444, ext. 208 > > Live Assistance, Please visit: www.ipexpert.com/chat > > eFax: +1.810.454.0130 > > > > IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, > Audio Tools, Online Hardware Rental and Classroom Training for the Cisco > CCIE (R&S, Voice, Security & Service Provider) certification(s) with > training locations throughout the United States, Europe, South Asia and > Australia. Be sure to visit our online communities at > www.ipexpert.com/communities and our public website at www.ipexpert.com > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Joshua Yost > *Sent:* Thursday, June 10, 2010 9:46 AM > *To:* ccie_rs > *Subject:* Re: [OSL | CCIE_RS] Sham WOW part 2 > > > > Any takers? > > On Tue, Jun 8, 2010 at 3:42 PM, Joshua Yost <[email protected]> wrote: > > I asked something similarly weird earlier, then gave up on it, but now I > have been testing it and am just confused > > Here's situation 1: > > R1------AREA0-----R2----------AREA111---------R3----------MPLS--------------R4---------------AREA > 222------------R5 > > > Now, without a virtual link through area 111, area 0 and area 111 are > isolated, and only know OSPF information from each other. This makes sense. > Now if I extend a virtual link through area 111 to the PE, I have > reachability to the Area 222. > > To break this down, and all sham link configurations set aside*, if I have > area 0 at any site in my MPLS VPN topology (as the customer), I must extend > it to the MPLS with a virtual link? Is that right? > > * > > Now, on to situation 2: > > > *R1*------AREA0-----R2----------AREA111---------R3----------MPLS--------------R4---------------AREA > 222------------R5----------AREA 222-----*----R1* > > Note this is a circle with R1 being an ABR for areas 0 and 222. > > Loopbacks are all R.R.R.R > > R1s loopback is in area 222 > R2 L0 in area 0 > R5 L0 in Area 222 > > So you can probably see where this is going, R5 - R1 would be my good ol > "Backdoor link" > > Right now with no manipulation, R2 gets to R5's L0 via R1 and the backdoor > link. In fact regardless of manipulation this is the case. > > Now, I want all traffic from R2 to area 222 to go over MPLS. > > So I configured the virtual link through 111 as described in the previous > example, then I configured an area 0 sham link over MPLS. Then magically, I > can route however I want over MPLS by playing with cost. Specifically, if I > want R2 to get to R5's loopback via MPLS, I just cost up the link between R1 > and R2 on R2. None of this works without the sham link, but I thought we > needed area 0 on both sides of the sham link for this to work? Is there an > exception? The sham link is acting kinda like a virtual link but not really. > HELP > > > > > > > > > >
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