Monday, April 13, 2015

Passing the CCIE (R/S) - A non-technical post


This is going to be me rambling. Fair warning.

I wanted to write down my experience with CCIE lab, now that I'm finally done. Not what technologies I saw, or who's workbooks helped the most (though I'm happy to answer those questions, so long as they don't violate NDA). This post is about the mental side of the CCIE, and I'll probably write a little bit about life ~two weeks after passing and getting my number.

A brief back story.

So I started my CCIE journey, unofficially sometime in 2011 (summer I think?). I passed my written on December 14th 2011 (version 4), and had my first attempt at the lab October 2012. My first attempt was such a rush, it was so great to be there in RTP... in the lab, I almost didn't care that I failed. I did pass troubleshooting, so I had that on my side, but the configuration section was brutal. I made some additional attempts in 2013, and was never met with success. I even went to a 5-day lab focused boot camp before one attempt. Still, no love. I remember riding home on the train (yes, the train) after failing the v4 lab, for what would be my last attempt at v4 thinking "Maybe I'm just not meant to pass this thing." I credit my wife with telling me that I needed to try one more time before she'd support me giving it.

2014 - too much happening

Towards the end of 2013 my wife and I decided to full-fill our dream of leaving Florida, and moving to North Carolina. With changing jobs (a couple times) and a second move to be closer to RTP, 2014 came and went. Very little studying and no attempts.

2015 - Let's make this happen.

In January I took a v5 mock lab and scored 95% overall. This got me excited about the technologies, and got me off my butt and back into labbing. I spent the next couple months dedicating ~10hrs a week to studying. Sometimes a little more, sometimes  a little less. Keep in mind, back in my previous attempts I dedicated 15-25hrs a week to studying. So I had a solid foundation, and felt that I needed to really work on strategy and lab changes.

I ran a number of mock labs, and made my way through workbooks fine tuning my own personal strategy. This turned out to be a BIG change for me, instead of approaching the lab the way others had told me to with a cookie cutter approach, I decided to read through each lab and develop a custom strategy for each. This resulted in, generally, very good scores and faster times. When I was about two weeks away from my lab, I decided that I would run (1) more graded mock lab and no matter the results I wouldn't run any more. Just focus on workbooks. Reason being is while I wanted to make sure I was on top of my game, I also didn't want to be burned out.

One week before the lab

So at this point, I've run my last graded mock lab, and luckily for me I scored a nice 85%. Not amazing, but hey it's passing. At this point I'm doing very little lab work, maybe spending an hour here and there working my way through a given workbook lab. Then 2 days before the lab, cutoff time. I had decided not to do anything, but maybe watch some video lectures at this point. Again, my thinking was "I want to be sharp, but I don't want to be completely burned out."

Night before the lab

I went to the store, picked up some things:



- Red bull (4 pack of 8oz cans - sugar free, don't want the sugar crash)
- Water, staying hydrated helps you stay alert and jitter free
- Trail mix, don't trust the lab food. The cake is a lie.

You should know that, yes they do feed you... but you shouldn't eat very heavy at the lab. Reason being, and this is a theory, they're counting on you going after the cookies and cake, eating a heavy lunch...ANNNDDDD crashing 2hrs before the lab ends. So I aim to eat a little protein, some fruit and salad. Anyway, back to the night before. For weeks I had been so cool, so confident. Then all the stress of passing the lab hit me like a ton of bricks, I slept absolutely terrible.

Lab Day. April 1, 2015 (April Fools Day)

I'm up at 5:30 am to get dressed, have breakfast, and make the drive to RTP to arrive at 6:45-ish. First things first, I slam some orange juice, vitamins, and drink a protein shake with some fiber added in. I should note at this point, I'm not a super fit person, but lab day is like running a freaking marathon, failure to treat it as such will leave you disappointed. So no caffeine yet, which is hard because I normally drink coffee before doing literally anything else. However, experience tells me I don't want to be jittering in my seat at the lab. So Red bull is on standby at this point. With some minor traffic on I-40, I still make it to building 3 around 6:50. This turned out to be completely fine as the proctor didn't arrive until 7:25 on this particular day.

Now you have to go through some pre-lab rules with the proctor. He (or she) is going to tell you some basic do's and don'ts. For example, no electronic devices in the lab, and only one person out of the lab to the restroom at a time, etc etc. This takes about 10 minutes or so. If you're in RTP, the proctor (Dave), will crack a few jokes to try and ease everyone's tension. Welcome the laugh, you'll need it you nervous wreck you!

Troubleshooting Section (120 minutes + up to 30 minutes borrowed from Configuration)

Crack open a Red bull, and go time!! I used one sheet of paper as a TPS so I could track what tickets I had completed, and how many points each task was worth. This was the most difficult troubleshooting section I ever had. I kept going through phases like
"I got this ticket"
"wait... no I don't"
"Oh God, I'm going to fail the lab again!!"
"Ok calm down, focus, try the next one and circle back to this one later."

Plan here was fairly cookie cutter, contrary to previous statements. Spend roughly 6-8 minutes on each ticket, if I couldn't figure it out I'd make a couple notes on my TPS about it and move on. When I reach the last ticket, circle back to beginning, rinse and repeat until all tasks were completed (or I had enough points to pass). I did have to borrow 15 minutes from configuration, but it was well worth it.

Diagnostic Section (fixed 30 minutes)

Guys and Gals... this section is weird. If any of you did the CCNP TSHOOT exam, it will feel sort of familiar. You'll be given a few scenarios, call it 2-4 different ones, where they outline a problem description (usually from the point of view of another network person). You'll also be given any relevant syslog, running configurations, network diagrams, and the original help desk ticket. With the help desk ticket they're giving you the problem from an end user's perspective.

With all that information at your disposal, you'll get some multiple choice questions. Before you have a sigh of relief about it being multiple choice, these are normally 2-part questions. I.e. for one question you have to select which device is causing the issue and which commands should be run to further diagnose the problem.


Configuration Section ( 5hrs 30 minutes + leftover time from troubleshooting)

So my configuration section was actually 5 hrs and 15 minutes, since I had to borrow time in TShoot. Now, here's a truth that all candidates need to accept about the configuration section (and really the lab as a whole). You are not going to get every point. If you hope to pass, you'll learn to pick your battles and make smart sacrifices. If you see a 4 point task that you're unsure about... but has the potential to break other tasks if configured wrong, well that's one you should eat the points on. I did that with (1) task in particular. I was 80% positive I could figure it out, but after spending 10 minutes on it and making no progress I realized "I'm wasting time, and furthermore if I misconfigure this I could break certain parts of my routing and cost myself 12 points... all for only a potential 4 points? Nope, pass."

It was such an insane day. I always thought that when I finally passed the lab, I would know it all day long. That is, during the lab I thought I'd never doubt myself and I'd finish 2 hours early. That's not what happened. I was panicking almost the entire day. I would force myself to stop and breath. Get up to go to the restroom. Just for a few minutes to calm down, and refocus. I honestly didn't think I had a chance until the last hour or so. Then I caught myself thinking "I might pass this thing today." I used every single minute, up until the last 5 minutes on the clock. However, I walked out the front door knowing I passed. I'd never felt so confident, and I'm so happy it was just.



About two weeks later

So I passed the lab!! CCIE 47884!! I was showered with rose petals, and I was given a 20k dollar raise! Oh and a new Macbook Pro retina!!!

Ha. Nope. Honestly, aside from me running around my house at 6 am the next morning when I finally got my results, it was pretty anti-climatic. A few congratulations at work, and recognition from colleagues. Which I'm totally OK with. This has been such an awesome experience and I wouldn't trade it for the world. My advice to other hopefuls out there? Don't quit. Getting your number is hard, and its meant to be hard. But never give up.



Sincerely,

Jon Major, CCIE# 47884 (yes, that number goes on everything I sign)

Thursday, April 2, 2015

CCIE# 47884

Can't. Stop. Shaking. I just got my results in and after nearly four long years, I'm a CCIE. More to come later. I do want to write up my general feelings on the exam, and what v5 candidates should expect.

Sunday, March 8, 2015

OSPFv3 for IPv4 (hooray address families!)

OSPFv3 is a pretty slick upgrade to OSPFv2. Most of us know as much, but in an IPv4 world we're all just stuck... waiting. Well with recent updates to IOS (I noticed it available in 15.3 - which can run on a 7200 in GNS3 for all you labbers at home) OSPFv3 now supports multiple address families. So much like with EIGRP named mode, we're seeing Cisco migrating routing protocols to follow the format of MP-BGP. The catch 22 with IPv4 routing with OSPFv3 you do have to have IPv6 unicast-routing enabled, AND all participating interfaces have to have IPv6 link-local addressing. The reason being, as we'll see in Wireshark, is that even though we're relaying information about IPv4 prefixes all communication with OSPFv3 is still done in IPv6. So let's get into the configuration, and we'll double back on packet level details.


Topology:



SP-METRO
!
conf t
!
ipv6 unicast-routing
!
router ospfv3 1
address-family ipv4 <-- support for VRF here!
!
!
interface Ethernet0/0
no switchport
ip address 200.1.1.1 255.255.255.252
ipv6 enable
ospfv3 1 ipv4 area 0.0.0.0
!
!
interface Ethernet0/1
no switchport
ip address 200.1.2.1 255.255.255.252
ipv6 enable
ospfv3 1 ipv4 area 0.0.0.0
!
!
interface Ethernet0/2
no switchport
ip address 200.1.3.1 255.255.255.252
ipv6 enable
ospfv3 1 ipv4 area 0.0.0.0

R1
!
ipv6 unicast-routing
!
router ospfv3 1
 address-family ipv4 unicast
!
!
interface Ethernet0/1
 ip address 200.1.1.2 255.255.255.252
 ipv6 enable
 ospfv3 1 ipv4 area 0.0.0.0
!
!
interface Loopback0
 description LAN NETWORK
 ip address 192.168.1.1 255.255.255.0
 ipv6 enable
 ospfv3 1 ipv4 area 0.0.0.0
Also we have very similar configurations on R2 and R3. After a few seconds you should see a nice console prompt "%OSPFv3-5-ADJCHG: Process 1, IPv4, ..." letting us know that we have an OSPFv3 peer within the IPv4 address family. Important take way from this is that if you do enable IPv6 address families, while it will run with the same routing process it does require a second neighbor adjacency. Another important note on that is if you're running both IPv4 and IPv6 address families, you'll have separate OSPF data bases for each addr family.

So show commands! Let's see what we get, then we'll take a look some wireshark info.

R1#show ip ospf neighbor
R1##CRAP
R1#show ip route ospf
R1##Double Crap!!
Wait?! What the hell's going on here?! I can feel the tension building at home, put your pitch fork down. I didn't lie to you. 'show ip ospf' explicitly refers to OSPFv2... and we don't have any v2 neighbors. Same with 'show ip route ospf', we don't have any v2 routes. Let's try this again.

R1#show ospfv3 neighbor
          OSPFv3 1 address-family ipv4 (router-id 192.168.1.1)
Neighbor ID     Pri   State           Dead Time   Interface ID    Interface
200.1.3.1         1   FULL/DR         00:00:39    17              Ethernet0/1
R1#show ip route ospfv3 | b ^Gateway
Gateway of last resort is not set
      200.1.2.0/30 is subnetted, 1 subnets
O        200.1.2.0 [110/20] via 200.1.1.1, 00:55:43, Ethernet0/1
      200.1.3.0/30 is subnetted, 1 subnets
O        200.1.3.0 [110/20] via 200.1.1.1, 00:55:43, Ethernet0/1

Like a promised, here's a quick wireshark off R1's Eth 0/1 interface, again important take away is that even though we're exchanging IPv4 prefixes, v3 send it's hellos and LS information with IPv6 addresses. If you go back to the configuration above, that's why "ipv6 enable" has to be enabled. Alternatively, you can also just assign IPv6 link local addresses manually... if you just like killing time.



Pop Quiz hot shot! FF02::5 is obviously an OSPF multicast address, but which one? Also what do you think the other OSPFv3 multicast address is? Answer here(select text after): FF02::5 is the ospfv3 all ospf routers group, like 224.0.0.5. FF02::6 is the ospfv3 DR group, again like 224.0.0.6.

The benefits of deploying OSPFv3 for your IPv4 networks are pretty sweet. The most obvious benefit, it lines you up perfectly for when you actually deploy IPv6 internally (in 1000 years). The next one, that I really like, you can start leveraging v3's security. That's right... IPsec. Lets take a look at that configuration real quick.

Now like ospfv2, authentication can be enabled per-link or globally for an entire area. I'll the area-wide method here, and cover the per-link in a future post/video (it's not vastly different).


SP-METRO
!
router ospfv3 1
 area 0.0.0.0 authentication ipsec spi 912 sha1 0123456789012345678901234567890123456789
 !
 address-family ipv4 unicast
!
 Notice on the area wide configuration you enable IPsec outside of any address-family. Again, making transitioning to IPv6 that much easier, you don't have to reconfigure security. So let's break this down. I think 'area 0.0.0.0 authentication' is pretty straight forward, so is the 'ipsec' portion of the command. Unless you didn't know OSPFv3 secured its routing with IPsec... then that might have been a surprise. The next part "spi" or Security Parameter Index, is a fairly arbitrary number between 256 and 4294967295. When enabling ospfv3 authentication per-interface the SPI has to be unique for each interface on the local router, and spi's have to match between neighbors. Area-wide, a single spi is just fine - since that's the only option for area wide authentication lol. After we specify an spi value we can choose to either use an md5 or sha1 hash. For SHA1 the hash value has to be 40 characters long, so for demonstration purposes I copied '0123456789' into notepad, copied and pasted three times. In the real world, obviously, you'll want something a bit more secure.


So there you have it! I'll have a video coming soon going into a bit more detail, but it's been a while since I posted anything and I thought this would be a good topic to start covering. 

Sunday, December 28, 2014

Where I'm at now...

So a quick update, I have passed the 400-101 (v5 written) and I'm back into full swing. Thanks to the awesome re-take policy iPexpert offers, my bootcamp is booked also. So if anyone out there plans to attend OWL in March, I'll be in RTP for that class. All in all, things are shaping up nicely, and I should meet my goal of an April Fool's Day lab attempt. Why April Fool's Day? Well, after sitting for the lab four times now, I've learned MANY things... one of those things is that you don't get to choose many things that happen lab day. You have no control over what your workbook is going to focus on. No control what food is served during lunch, or what computer you sit at during the lab. You can't even pick your own terminal emulator. One thing you do definitely have control over is what day you take your lab, I choose to take mine on a day that makes me smile.

Wednesday, November 26, 2014

EIGRP OTP - Looking closer part 1

So I'm going to break my closer look at EIGRP Over the Top into a couple smaller posts. Maybe I'll tie it together with a video when I'm done... maybe lol.


So today I thought I'd answer the most basic question of OTP, how the hell does it work?! In my previous post I covered a quick setup of OTP, and talked a little bit about the need to have connectivity between nodes. To reiterate that, the only way I could get OTP to work was to have a static route on each CE device pointing to my MPLS cloud for all other CEs (their MPLS facing interfaces only). That sounds confusing so here's a picture!


Now that you have a visual, all I did so my CEs could reach one another was add a static route 10.255.254.0 255.255.255.0 10.255.254.y where 'y' is the PE for each host. The reason I take time to point this out, again, is because OTP is advertised as an overlay so you don't have to do any dynamic routing with your provider. What it's not is an overlay where you don't have to do ANY routing with your provider, you CEs have to be able to be able to reach one another. Ok, now that I've touched on that fairly obvious topic let's get into some packet captures. What traffic is your provider going to see when you're running OTP?


EIGRP: Your provide CAN see EIGRP packets, again a lot of documentation talks about LISP encapsulation, and it's definitely there... just not for your actual EIGRP traffic. This is may or may not be of concern, but I wanted to throw it out there. I ran a wireshark capture on the PE facing CE3, and here you can clearly seeing that we're sending EIGRP packets without LISP encapsulation.



Also a quick note of on the topic of EIGRP packets, remember in the last post that your EIGRP RR clients need to have a maximum hop count specified for their static neighbor command? You don't remember that?! That's fine, here's what the syntax looks like:

router eigrp OTP
 !
 address-family ipv4 unicast autonomous-system 300
  !
  [...]
  neighbor 10.255.254.2 Ethernet0/0 remote 10 lisp-encap

I used '10' as the maximum hop count. Well, you can actually see that in the capture as CE3 -> CE1's TTL value in the IPv4 header. I know that's pretty basic, but I love seeing evidence that something is working as expected.




LISP: Ok so you might be wondering... where does LISP come into play? Well, let's look at the routing table on CE3, specifically at EIGRP learned routes.


CE3#show ip route eigrp | b ^Gateway
Gateway of last resort is not set
      192.168.1.0/32 is subnetted, 1 subnets
D        192.168.1.1 [90/3584640] via 10.255.254.2, 00:09:08, LISP0
      192.168.2.0/32 is subnetted, 1 subnets
D        192.168.2.2 [90/3584640] via 10.255.254.6, 00:09:08, LISP0
CE3#
There's your answer! Any traffic destine to those EIGRP learned prefixes, will be LISP encapsulated. Which brings up a fine point... what does LISP encapsulation actually look like? Well, Cisco's current documentation notes that user data will be encapsulated udp/4341 (ref:here). However I did not find this in practice. For a test I initiated a telnet from CE3 to the loopback address of CE1. Check out the wireshark.



So data is actually being encapsulated udp/4343. Just for fun, let's decode this capture as LISP. If you're not familiar with that function within wireshark (works on ALL kinds of protocols), what I'm doing is going to Analyze > Decode As...>LISP Data. 


Check it out! There's all my decoded traffic, as you can see I sent some pings before firing off my telnet session. I know what you're thinking... I can sense it even now. You're wondering if I can follow that TCP stream (that was encapsulated LISP) and read the telnet output aren't you? Yes dear friend, yes we can.







So that's it ladies and gents, part 1 of my closer look at OTP. Not sure what part 2 will be about... but I'm thinking I might combine OTP with GETVPN, then maybe look at VRF support. 

Monday, November 24, 2014

EIGRP just went... Over the TOP!





So I did a short video with my initial configuration/look at EIGRP OTP. Just thought I'd share it out here as well. I'm going to be looking into it a little more in-depth in the next post, but until then!






Sunday, October 19, 2014

New Trouble Ticket -- OSPF NSSA and full reachability

So I bumped into a pretty similar task in my studies not too long ago, and decided tonight that it would make for a pretty good blog post. So first things first, here's our network diagram (sorry it's not as pretty as usual, but suck it up butter cup).



If you're going to attempt the following task, you can IP the connections between routers however you like. I did 192.168.xy.z/24 where x is the lower router number, y is the higher, and z is the router number. So the link between R1 and R2 is 192.168.12.z/24. That being said here are the conditions of the task.

1. Area 13 MUST be an NSSA area.
2. Each router can only have a single OSPF process.
3. You may not add any additional interfaces.
4. Only loopback 0 may be advertised into OSPF using network statement, and it may only have the IP of "192.168.z.z/32" where z is the router number. All other loopbacks must be redistributed into OSPF.
5. No static routes are allowed in this lab.

That being said here's the task.

Both R3 and R4 are redistributing a number of Loopbacks into the network. R3 is an NSSA router, configure R3 to advertise Loopbacks 6, 7, 12, and 13 as a single summary. This summary must been seen throughout the OSPF domain, but should not hinder full reachability. When this task is completed all loopbacks should be reachable from all routers.