Passed MPLS and BGP

I passed the MPLS and BGP exam on Thursday. This time around the questions seemed harder, but with the extra couple of weeks of study I passed fairly easily. Looking back on it I should have done the separate exams. The MPLS Fundamentals book is good, but not enough for the exam. There were a few things I had to rely on the "MPLS and VPN Architectures CCIP Edition" book for. I had underestimated the BGP section. While I have worked for an ISP before I didn't really understand some of what was happening under the covers (even though I new enough to make BGP do what I wanted). The "Internet Routing Architectures" book is still one of the better books for this exam, but it is not enough. I would say you need to do a little general design research as well.

On to BSCI. I am not really in a hurry to do the exam - I am planning on doing enough routing, IPv6 and Multicast study for the BSCI so that I am at CCIE written level. Once I have done that I'll do the exam then move on to studying the rest of the CCIE written.

BGP and MPLS exam

I've bitten the bullet and scheduled the MPLS and BGP exam for tomorrow. I've really spent way more time tinkering with BGP in the last week than I have with MPLS. That's probably more of a reflection of where my current interest is than what I need to know for the exam. I am happy with what I know about BGP now (I'd call it almost CCIE level knowledge). The MPLS study that I have done over the last week has been mainly focussed on the MPLS VPN and basic MPLS subjects. I did a final read through of the ATM subjects in the Fundamentals book earlier in the week (I know that is a bit of a weak spot in my knowledge). I haven't really studied AToM and VPLS that much in the last week, I don't really know them in depth but I am happy that it will be enough for the exam.

The things I KNOW I need to remember for the exam are:

• You need to be able to route to the IP address used for the router-id by LDP in order for an LDP session to establish (I keep reminding myself and forgetting when I lab something up)
• The different VPN types and overlay, peer-to-peer, extranet etc.
• BGP route selection process (really happy I know my stuff for this)
• Configuring VRFs and using multiple route-targets to allow overlapping and other types of VPNs.
• Using OSPF between the CE and PE routers (sham links are something I spent a while playing with on dynamips)
• Confederations, Route reflectors and how they impact BGP advertisements.
• BGP attributes and how to change them and what they REALLY do
• Multi-protocol BGP - address-family vpnv4 and address-family ipv4 vrf and what to put under each

I am sure there will be some general MPLS and LDP type questions (ie what tag would router x use to forward a packet, how does the icmp packet too big get delivered, how does LDP find neighbors etc). I am pretty happy I have that sorted.

I'd have to say once I had done an initial read of a few books I got the biggest value from using dynagen / GNS3 labbing things up and using wireshark to look at packets. I really understood HOW LDP worked once I saw the packets. The book didn't really say why LDP used a UDP stream and a TCP stream. After seeing it the UDP stream is just for hello packets and finding a neighbor via multicast. The TCP stream is for advertising labels (using the LDP router-ids for the source and destination). Why couldn't the Fundamentals book just say that?

The other thing I am always slipping up on is BGP neighbor establishment. I have a habit of mistyping IP addresses, mistyping AS numbers or forgetting eBGP multihop. I tend to struggle for a while and turn on debug ip bgp and then just recheck my configurations. I keep forgetting how powerful the show ip bgp neighbors command is.

CCIP MPLS and BGP combo exam

I've decided I am going to do the CCIP combo MPLS and BGP exam. There are a couple of reasons - the biggest one is time. I really want to get the CCIP out of the way before the end of September and the CCIE written done by the end of October. Realistically the CCIE written exam will probably take more than a month to study for (even though September will be routing month). Even though I am going to do the BSCI in September (my BSCI exam expired about two or three years back) I still think I'll need a good four weeks for the CCIE written - between switching, multicast, frame-realy and QoS. It should all just be revision as I did the written a few years back and have done some hard core study for it a few months back.

I'm half thinking i should book the combo exam for two weeks time to put a little pressure on myself (I'm easily distracted at the moment). Looking at the BGP exam outline I keep thinking how hard could it really be... and then I remember how hard it really can be.

Back to the books.

MPLS Fundamentals

I've finally finished reading and noting the CiscoPress MPLS Fundamentals book. It's only appropriate that I give my thoughts on the book. I was hoping it would be a bit like the Routing TCP/IP book - an easy read which slowly builds your knowledge until you look back and say "Oh my gawd how did I learn all that?". Well it was nothing like that. Some chapters were really "crunchy" full of facts and not enough words to make it clear or easy to read. Other chapters were just plain repetitive (the QoS one for example). I found it a little annoying how it introduced subjects. Often there would be two alternatives presented in a reasonable amount of depth followed up by a paragraph saying... "Cisco implemented option 1". There was also some plain bad editing - at least a few places where the example did not marry up with the text around it, and some where they talk about some numbered items and refer to one that doesn't exist in their list (ie they'd have a list of 4 items and refer to item 5).

Even after all of that I'd have to say I don't regret getting the book. It did cover most of the topics that are in the CCIP MPLS outline to a reasonable depth and covered a few extras that are useful. There were a few chapters that I could have skipped - but I read them anyway because the CCIP MPLS outline and the associated course differ so you can't be too sure what really is going to be on the exam. My recommendation would be to read the MPLS Fundamentals book cover to cover before you start writing notes. Then start again from page 1.

There is still a bit of a gap betweeen the book and the exam outline, so I am going to do a little more reading (not sure if I will grab another book or hit the DocCD and Cisco site). Either way I think I have about two weeks before I'll hit the exam - I'd like a week of solid GNS3 work at night as well as a while to go through my notes and flesh out the bits that the Fundamentals book didn't cover.

MPLS QoS

I'm about 80% of the way through the book. My last week has been a study disaster. I've been busy at work and coming home feeling very flat and unmotivated. Luckily next week I should be doing some MPLS proof of concept and design work. This should mean I get to tinker with some MPLS VPN and QoS at the very least. Hopefully I can justify a little AToM and VPLS as well (we will eventually need to integrate one or both into our network).

MPLS VPN

I'm about half way through the MPLS Fundamentals book. My opinion of it varies depending on the day. Sometimes it is clear and well thought out. Others the example configs don't match with the text and sentances make MPLS more confusing than it needs to be. I quite enjoyed the MPLS VPN section (in a wierd sort of way). It is good to see the more curious ways that BGP and OSPF can be configured. The use of communities to exchange EIGRP route properties via the provider's MP-BGP is kind of nifty too.

I'm planning on ramping up my study for the next two weeks so that I can polish off the exam late this month or very early next month. I'm already starting to look for a good BGP text. At the moment I think I am going to stick with Routing TCP/IP volume 2 plus a generous helping of the DocCD. Word from Cisco is that they are going to make more of the configuration guides into full book pdfs. I hope it happens before the end of the month (nothing annoys me more than having to download 8 or 9 PDFs to work offline with for one protocol).

More MPLS

I'm about 20% of the way through the Cisco Press MPLS Fundamentals book. I've found it a bit of a slog this week. The book is an easy read for the first chapter or so, then it gets fairly dry for a while. I prefer to go through a bit of practical (show me the commands to keep my interest). Unfortunately the book is focussed more on the theory before showing you much of the CLI. The last chapter has been very repetitive, but at least it has had some commands and their output.

This week at work (first week in a new job) has been interesting. My brief for the week was to just "poke around" and see if I can find any issues in the network. I've cleaned up the world's worst Visio diagram (who in the world creates a text label for a router out of about 10 or 15 different text fields (one for each octet of the IP address, one for each of the dots, and one for each part of the router name). I've also spotted a wole heap of other issues. Spanning tree and VTP are a big issue - too many VLANs (more than the number of spanning-tree instances supported on most of the switches) and more than the number of VLANs that some of the switches support. It also appears that VTP pruning doesn't work as promised (most places I have worked haven't had that many VLANs, or have used transparent mode, so I haven't seen that before).

We've also been looking at using 31-bit masks on some of the links rather than the /30 masks we are currently using. Since we have a whole heap of those links it will make a considerable saving in the address space.

Well - it's off to do some GNS3 work on MPLS.

Starting on MPLS

I decided to cut the cord on the Juniper study. It isn't really relevant to my new job, and I really wanted to get onto my CCIP study (so that I can get it over and done with before I get back to CCIE study). I finished writing my notes and did the exam on Tuesday without much real revision. I missed out on passing by 4 points. I would have preferred to fail by a heap (at least then I wouldn't regret taking the exam so quickly).

I've started my study for the CCIP MPLS exam. There's a lot of conflicting reports on which books to use if you are self studying. I've read a few that say to avoid the Sybex MPLS book. It's a bit disappointing - I've found them to be good in the past. Instead I have decided to go through the Cisco Press MPLS Fundamentals. After that I'll take a look through the MPLS and VPN Architectures books to clear up anything that the Fundamentals book misses. If there's still some holes I guess it is off to the documentation CD. I guess I will probably skim through some MPLS sections on the DocCD - I got caught last time I did my CCIE Written and now I'm a little gun shy on doing an exam based on just one or two books.

So far I'm about 10% of the way through noting the Fundamentals book.

Distractions

At the moment I am sufferig from a few distractions - the Juniper switching exam (from Juniper's fast track) and a change of job happening in early July.

I'm hoping to polish off the Juniper exam very soon (I've half finished noting the study materials and I'm waiting on the Exam Voucher), but can't find a testing spot until early July. Once that's sorted I am planning on studying hard and fast for the MPLS exam from the CCIP. I may follow that up with the BGP exam from the CCIP. Both are going to be very important in my new job.

Unfortunately both will set my study for the CCIE written back some way - at least the MPLS is partially relevant to the written.