CCIE Study Notes

With over 10 years in Networking, I may be tempted to skip this part. However, it's always good to review. Yes, we are very familiar with the /8, /16 and /24 subnets. And network engineers have /30s and /23s down pat for the millions of times we've configured them on networks. And the CCNA and CCNP courses/exams have gotten us to where we can subnet IPv4 in our head. Some tricky questions could force pen to paper to work them out, but they're not that hard. So what else could be covered with this topic?

Let's start with the recommended reading materials. The CCIE Security Written Exam Guide (Cisco Pocket Guide) covers this in just a few paragraphs. It assumes you already have a thorough understanding of IP addressing and subnetting. Great. We do. But wait one minute. Do you really think you're going to get an IP subnet question on the CCIE exam? Yeah, you could. But that would be a gift. And a straight forward calculate the subnet question really isn't a CCIE level task. So why is this listed?

One of the other places to look is the Cisco Documentation. Since you are not in front of any exam, you have the opportunity to use the Search in the Cisco Documentation to find as much information as you can digest about the topic. Although the Cisco site is constantly being reorganized, here is the link to IP Addressing Services in the Cisco Documentation.

Access lists are more appropriately covered under their usage. Dynamic Address Allocation and Resolution. Hmm. That might be worth a peek. DHCP is covered later in the blueprint. However, there are Design Tech Notes, Configuration Examples, Maintain and Operate Tech Notes and Troubleshooting Tech Notes under this topic.

Another interesting guide is the "Subnet Zero and the All-Ones Subnet." That's something that you may want to review. It's not something that you run into or think about every day. But it's a detail that could appear on an exam that is measuring expert-level knowledge. The article actually explains the issues very well. But what you should really remember is that after IOS 12.0, this is not a problem.

Although DHCP is covered later, I did look at "Understanding and Troubleshooting DHCP in Catalyst Switch or Enterprise Networks" page. Just in case I forget to mention it later - there is a really good section in that document. The troubleshooting steps in the Case Studies are routine. But go to the DHCP Troubleshooting Modules. The first several items are routine. But then keep reading. Did you remember that DHCP snooping automatically enables option 82? And it's not the type of thing that you may have run into. But someone else might have experienced that and thought it might make a good test question. Also remember - anything (ANYTHING) in the Cisco Documentation could end up on the Written Exam.

Network Address Translation is another topic that is covered later in the blueprint. It's probably best to focus on that later on where it is more relevant.

The Technology Q & A section has an interesting ARP Article. Why are some dynamic ARP entries still present in the ARP table after the respective ARP timeout has expired? So if you thought you knew ARP, and you got a question about Random Jitter being added to an ARP cache timeout - would you know this was a real thing? Normally we talk about jitter in voice and QoS realms. But this is added to the ARP cache timeout to prevent a bunch of ARP entries from expiring at once and triggering an ARP storm.

By the way - I just noticed that there are TWO areas to find IP Addressing Services.
1 - The old site (based on the layout) showing the overview
http://www.cisco.com/c/en/us/tech/ip/ip-addressing-services/tsd-technology-support-technology-information.html
2 - The new site (based on the layout) showing IP Addressing Services
http://www.cisco.com/c/en/us/tech/ip/ip-addressing-services/index.html

The old site

The new site

Clicking on the links at the old site brings you to the new site. I only mention it in case some of the links in this post break when Cisco updates their site. They do this frequently. Remember that. It will apply to your lab. For the lab portion, you are allowed to use the Cisco Documentation. This is because they don't really expect you to remember every last detail (like default timers or some corner case application of the technology). But they do expect you to be able to find it quickly in the documentation and apply it to your lab scenario. Oh yeah - and the search is disabled, so you have to know how to navigate the documentation manually (click by click). So be very familiar with the navigation - even as it changes. The lab currently costs $1600 USD. If you know where something is and you can't find it because it was moved, Cisco will not give you a "do-over" or any sympathy. It's your responsibility to keep up with this stuff.

And that brings me to the end of Part 1. Yes, there is a Part 2. Notice that all this is about IPv4. Look at the blueprint. Do you see a section on IPv6? No, it's not there. It's embedded in all the other topics. If you are in the US, you probably don't work with any IPv6 yet. But in quite a few areas around the globe, IPv6 is used extensively. Cisco is a global company - expect the exam to reflect that. Previous versions of the R/S CCIE Written covered IPv6 as a topic. Having passed that test (3 times), I thought I knew as much as I needed to know about it at this time. When I took the CCIE Security Written exam (Jan 2016) I learned a very expensive lesson. You need to know IPv6 as well as you know IPv4. Convert yourself to a dual stack model. Remember that the test is adaptive. If you blow an IPv6 question (that you could have answered for IPv4 easily), you will get hammered with more of them.