IE Vol 1: VPNv4 Route Reflection Complete

This was an interesting lab that took a heck of a lot of time to just reconfigure the topology.

Essentially, the configuration ends up with two separate route reflectors--one for ipv4 routes and one for vpnv4 routes. Amazingly, no real complex configuration is required. There's no need to mess with clusters or anything like that. Instead, simply configuring the route-reflector-clients under vpnv4 instead of directly under the bgp process takes care of it.

I did run into two issues due to simple mistakes. First, one of my PE routers showed all MPLS labels as being untagged. This was due to me forgetting to turn on cef on one of the P routers.

Second, one of my CE routers was not learning any RIP routes. This issue actually threw me for a loop for a bit. It turned out that on the PE router I didn't set RIP to version 2 under the appropriate address-family. By default, rip sends version 2 and receives versions 1 and 2. But when version 2 is specified, rip only sends and receives version 2.

Since the PE router did not specify, it received the version 2 routes from the CE router and entered them into the routing table. It also redistributed its bgp routes into RIP and sent them as version 1.

Since the CE router specified version 2, it ignored the version 1 routes sent by the PE router.

IE Vol 1 OSPF Domain-id complete

This was another interesting lab. Typically in MPLS, redistribution is done from OSPF to BGP and back to OSPF in order to connect OSPF together across the P network. Because of the redistribution, OSPF sees the remote sites as External (LSA type 5) networks.

But since these remote sites are likely to be within one company's control, having them marked external may not be the best option. Instead, the domain-id can be used on the PE router under the ospf process. When the PE router advertises the ospf route to the CE router, it looks at the domain ids of both routes. If they match, the ospf route is advertised as an inter-area (IA) route instead of an External route.

This seems like it would be important for a couple of reasons. IA routes are always preferred over E routes. Also, E routes are not advertised into stubby areas, while IA summaries are. In more complex scenerios with a mix of nssa areas and redistribution, a company may prefer to use its provider's MPLS network rather than another non-MPLS link. The domain-id allows for this much easier than filtering routes from the edges.

IE Vol 1 OSPF Sham Links Complete

This was an interesting lab on two levels. It was the first time I have configured isis and ospf sham links are an interesting subject.

I was really amazed at how easy it is to configure a simple instance of isis. Just configure a net address and throw isis on the interfaces, optionally set the interface type, and it's complete. No issues there.

OSPF sham links, on the other hand, I found to be a a much more complicated subject. Its purpose is to deal with a customer that has non-MPLS links neighboring via OSPF, yet the customer still wants to route this traffic over MPLS.

Once these OSPF routes hit BGP, they are seen as iBGP routes, which as an AD of 200, as opposed to the OSPF AD of 110. This means if the prefix-length and default AD is the same, the OSPF route is going to be entered into the routing table.

To prevent this, an ospf sham link must be created. This is configured by setting up an additional loopback interface on the PE router and adding it to the customer VRF. Next, these loopbacks need to be redistributed into the bgp ipv4 vrf. Once the loopbacks are reachable to each other via the P network, under the ospf vrf process, enter area 0 sham-link source-ip dest-ip. This, somewhat similar to a virtual-link, creates a logical link between the newly created loopback interfaces. Then, the path is seen via ospf rather than bgp and the MPLS route can be preferred over the customer link.

Study Plan

The following is a rough draft of my SP Lab study plan. I don't have a date set yet so this will become more precise once I do. I plan (so far) to use Internetwork Expert for all of my studying. The basic timeline that was successful last time was 1 month of studying one practice lab per week, and then two months of two practice labs per week leading up to the actual lab.

Already completed: Volume 1 MPLS VPN labs.

Week of 12/21: Remaining Volume 1 MPLS labs.
Week of 12/28: Volume 1 Multilcast labs.

1/4: Volume II lab 1
1/11: Volume II lab 2
1/18: Volume II lab 3
1/25: Volume II lab 4
1/31: Volume II lab 5

2/1: Volume II lab 6
2/7: Volume II lab 7
2/8: Volume II lab 8
2/14: R&S Graded Mock lab
2/15: Volume II lab 9
2/21: CCIE Assessor R&S
2/22: Volume II lab 10
2/28: R&S Graded mock lab
2/29: Repeat of one of the Volume II labs

So this puts me taking the lab sometime in March. Hopefully I can find a date around there. I'm still waiting for my exam to clear the CCIE site so I can see what dates are available. I should know within the next day or two.

SP Materials, and lack thereof

I don't have a lab date setup yet, but hypothetically I'd like to take the lab around April. I know from R&S that I need a good three months to prepare.

There are only 10 full Volume II labs in the Internetwork Expert labs, as opposed to 20 in the R&S curriculum. I wouldn't expect this to be too much of a problem since I really only went through 10 of the full workbook labs for R&S anyway.

That leaves 3 main gaps to cover. In R&S I relied heavily on a one week bootcamp, about 5 graded mock labs, and the CCIE Assessor.

In actuality, those three pieces were the most helpful to get me ready to tackle the CCIE itself, rather than specifically R&S material. So I think I can still take a couple of graded R&S mock labs to ensure my accuracy is ok. I'm hoping I won't need a bootcamp this time around, but I'm open to it depending on how the studying goes.

SP Community

Thanks to everyone for their positive comments over the past week. It's nice to see there are few others out there working on SP as well. Sometimes this feels like the loneliest CCIE since there's an absence of graded mock labs, groupstudy forum, and not many posts in the other forums out there. The rest of the non-R&S CCIE world seems to be working on Security or Voice for their second.

Good luck to Route Target as well, who will be taking his SP lab in February.

Passed CCIE SP Written 350-029

I thought I'd take a stab at the SP Written before year's end. I've heard rumors that this exam wasn't nearly as nasty as the R&S Written.

There was the standard 10-20% of questions that were just plain ridiculously hard. Aside from those, I'd say easily 50% of the exam is pretty basic to anyone with a CCNP and CCIP level of knowledge. Heck, quite a few of the questions were more on the CCNA level to be honest.

So that leaves the remaining 30%. They were difficult but strangely it was pretty easy to weed out the wrong answers. The usual questions such as, "Pick the best 4 out of 6". I'd have no idea about the 4 to pick. But two obviously didn't belong since they were part of a different technology altogether.

As far as written exams go, I'd rank them as follows in order of difficulty:

BGP+MPLS: 10
R&S Written: 9
Remaining CCNP and CCIP exams: 8
SP Written: 7
CCNA: 5

That's how I feel. If you know the CCIP and CCNP material, 50% the questions on the SP Written exam are actually easier than what's found in the professional level. So if you can deductively eliminate incorrect answers and get lucky on a few of the other half of the exam, you should be able to pass it.

And now it's time to begin studying for the lab. I'll put a study plan together in the coming days. I'm hoping to shoot for my first attempt in April or May.