Whether you are studying for a certification exam, wanting to retain a skill set, or just trying something out, a lab environment can be incredibly helpful. This is nothing new and many people will give this recommendation, I just feel strongly enough about it to echo the advice. There is just something about learning by doing that really helps it stick, and repetition is key.
So, you want to be able to “lab things up”, now what? I’m sure you can find many debates on the internet about whether physical gear is necessary or if virtual labs are “good enough”. Here comes my favorite answer, “it depends”. As with anything, you need to start with requirements. What exactly are you trying to do? My requirements have generally been certification study and having the ability to quickly test something or prove a concept. Personally (at least at this point in my life), I’m not a fan of having a bunch of gear at home (bring on the heckling). For my CCENT/CCNA studies, Cisco’s Packet Tracer application got me most of the way there. I only remember one or two concepts that I used real gear for because the concepts were outside of the scope of Packet Tracer. For my requirements now, I have been using Cisco VIRL. You get to run Cisco images on virtual gear, and that has been plenty for me. I can either build labs from scratch, or have VIRL automatically build the basic configurations (such as L3 interfaces and dynamic routing) and I can focus on specific concepts. Again, for you, it’s all about knowing what you are trying to accomplish and picking the best options (physical or virtual) to meet those needs. If you ever need a little motivation around this, I recommend checking out:
Du’An Lightfoot – @labeveryday on Twitter – Passionate network engineer and an incredible community influence.
The Art of Network Engineering – @artofneteng on Twitter – Discord (This is where all of the community magic happens) – Great group of people discussing, listening, and learning together.
I take my work, and career in general very seriously. Not only because I have a family, but I am fortunate enough to be passionate about my work. I thrive on having a purpose. I also have a constant desire to learn and grow, and in the last year or so, I started getting into listening to tech-related podcasts. Due to some solid advice (thanks Greg Ferro), that turned into writing, and now engaging with others in “the community”. I put “the community” in quotes to point out that I think it can mean different things to different people. In the rest of this post, I’m going to share with you my interpretation of the IT/networking community as well as my experiences so far.
From an IT/Networking standpoint, the community isn’t one single, solid thing. It is a grouping of individuals (actually multiple groupings) passionate about their work and improving their knowledge and skills. That being said, it’s also much more that, which is where the biggest benefit lies. The members of the community are also passionate about sharing thoughts, ideas, tips, and experiences for the purpose of creating conversation and helping others. I’ve only been participating in the community for a short period of time, but I’m already amazed at how involved other people get. It’s important to mention that there’s no obligation to this. It’s people helping people because they can and to grow the community. I won’t claim the know the reason why others participate, but I do so for the following reasons.
- Communicate with like-minded individuals and gain this sense of community.
- Learn different perspectives on different topics.
- The ability to ask for help.
- The opportunity to provide assistance.
I’ve been amazed so far at the lengths that people and groups have gone to connect with and help others in the IT and specifically network infrastructure fields. I’d like to provide a few communities/people to follow. I encourage you to just get involved, have conversations, and stay connected. It’s pretty powerful.
- The Art of Network Engineering (GREAT community resources)
- Discord (This is where all of the community magic happens)
- Look for Art of Network Engineering in your favorite podcast app.
- Packet Pushers (Lots of podcasts, blogs, community resources)
- Gestalt IT (Tech Field Day resources, podcasts, videos, blogs)
- The CTO Advisor (Commentary and insight on modern infrastructure technology)
As I continue to prepare for the Implementing Cisco Enterprise Network Core Technologies (350-401 ENCOR) exam, I wanted to give an update. The main reason for this post is to share some small “successes” in an attempt to give you all some encouragement to get out there and learn. I wouldn’t call myself an expert in anything, but I have a constant curiosity and drive to move forward, which is good enough for me. What I think really makes learning worth it are those “ah-ha!” moments when things just start to make sense. There are a couple of topics that haven’t been the clearest to me in the past, which are multicast and QoS. I’ve never really taken the time before now to really understand the concepts. When approaching these in the past, I’ve tried to go in depth right away versus trying to understand the basics first. This is one reason why I like studying for certifications. It gives you the opportunity to understand to understand the concepts and the “whys” instead of just the “hows”.
My questions for you out of this post are what drives you to learn and what are the tools and methods you use to get the best result out of learning something new?
Over the years, I have had an “on again, off again” relationship with IT certifications. I tend to take what I think is a long time to prepare, and I’m not a fan of failing when I have dedicated so much time to preparation. I won’t say that my reasoning for pursuing certifications has changed over the years, but rather evolved. My reasoning started with trying to advance my career and get that next job. While that reasoning continues, I have also added the concept of certifications as an “insurance policy”. The primary goal of my career is to be able to provide for my family. If that worse case scenario were to happen and I need a new job tomorrow, I want as much as I can put on my resume to help it float to the top of the stack with hiring companies, and I believe that certifications are a part of that. I still believe that knowledge and experience are key, which you can have without certifications, but I want that “insurance”.
I would say that career insurance and progression are my main reasons for pursuing certifications as this point in my career. That being said, there were multiple times over that last ten or so years that I wasn’t sure if that was enough. Was learning the certification curriculum for the given cert the best way to learn applicable skills to my current job or the next one that I wanted? This is where I think it’s important to do at least a bit of high level planning. I think you need to know what you want out of a certification and the training that comes with it to decide if knowing that curriculum is “enough” for you to be satisfied. For now and the immediate future, I’ve decided to be focused on Cisco Enterprise technologies. Between CCNA and now CCNP studies, I have been happy with what is in the curriculum. I am learning things in the curriculum that I didn’t know in depth before, but are applicable to my current role. That is very rewarding for me and is part of what makes this whole process worth it.
I would love to hear what your reasoning is to, or to not, pursue IT certifications. I think there is a lot of good conversation around this topic.
When deciding on direction, tools, and ultimately purchases related to IT in an organization, it is very easy to get caught up in trends and buzzwords. Every product and service can quickly become the “next best thing” and you don’t want to be left in the dust, right?
I do believe that in order to make intelligent decisions regarding the direction of your company, you need to be informed on new technologies and services. Whether you are researching on your own or getting this information from a partner, it’s definitely a good thing to do. Having knowledge of these technologies and services will help you if you need them at some point to serve a business need.
The two important words at the end of that last sentence are “business need”. As an IT professional, your ultimate goal are to serve the needs of the business. If you are someone in the organization responsible for making IT related decisions, it’s my opinion that you really need to understand what your business is doing and where it is going to provide proper value. Remote access throughout the pandemic is an example of this. How do people need to connect and what do that need to do? Maybe a “one size fits all” approach meets the need, and maybe is does not. Understanding the tech is obviously important in IT, but understanding the business is just as important.
Last week, I was able to attend a fair amount of the virtual Cisco Live US 2020 event. I wanted to share my thoughts around the social aspect of virtual versus physical conferences.
Up until now, I have only attended one Cisco Live US event and that was in Las Vegas in 2017. I remember getting registered late and not preparing the best for the event. It was overwhelming to say the least, but I had a great experience. I attended multiple sessions and met with a few people, but largely kept to myself. I’ve learned since then that I did it wrong. A big benefit of these conferences is to meet and network with like-minded people. The social aspect of these events is huge. I was really looking forward to giving it another go this year.
I think that currently, virtual conferences make social interaction more difficult because there is less chance for organic conversation. I say “more difficult”, but definitely not impossible. We have been using videoconferencing technologies for some time now (and is used to supplement these virtual conferences). I definitely think that virtual conferences are here to stay and that’s a very good thing. They promote inclusion by making it easier for people to join in without travel. I do think that we need to be careful that we don’t let the interaction, organic conversation, and general people networking go by the wayside. We need to continue to leverage technology to stay connected, when we cannot meet face to face. In my opinion, humans are the heart technology.
I am currently working toward achieving the CCNP Enterprise certification. I thought it might be fun and interesting (relatively speaking) to create blog posts around some of the topics I am covering throughout my preparation. I recently spent some time going over virtual routing and forwarding (VRF). Up until now, I haven’t had a lot of direct exposure to VRF. I had somewhat of an idea of the purpose, but it was mostly magic and unicorns as far as I was concerned. As I dug into the technology, I quickly realized that it’s a really simple concept with fairly simple configuration (the high level basics, of course). We virtualize everything these days, why not routing tables? Maintaining route separation with being able to use overlapping networks in separate VRFs can be very useful. My advice to anyone else learning about VRF (along with practically every other networking technology) is to find a way to lab it up, play, and test. This isn’t new advice by any means, but I find it really helpful. Being able to apply learned concepts in practical examples is really powerful. Plus, having “ah-ha” moments while going through practical application can do wonders for your confidence.
Happy learning, and remember to help each other out there.
Disclaimer: There is a fair amount of my opinion in this post. I welcome feedback, especially on anything that doesn’t seem right.
When discussing and thinking about campus networking, I go back and forth on where the L2/L3 boundary should be placed. In a traditional three tier architecture of core, distribution, and access, how far toward the access layer should we take routing? Of course, that answer is probably the all popular “it depends” reply.
My thought is that with multi-layer switches being common for some time now, and that modern switches (depending on what you’re dealing with) can function at Layer 2 and Layer 3, taking routing all the way to the access makes sense. My reasoning behind this is simplicity and bandwidth. Spanning Tree Protocol does its job well, but if I don’t even have to think about STP, generally I’m happy. On the bandwidth side, leveraging Layer 3 means we can reap the benefits of Layer 3 Equal Cost Multipath (ECMP).
That all being said, any design should be approached by understanding the business requirements. Is there a business need to have VLANs span multiple switches? If so, and if there is no overlay technology in play, then Layer 2 from distribution to access is necessary, which is still a valid design. Also, to maintain redundancy and utilize more physical links, Mutlichassis Etherchannel (MEC) supported designs can be deployed.
In conclusion, I think it is great to have standards to strive to implement, however you always need to be mindful of business requirements. I do think that overlay technologies will continue to become more prevalent and allow for standard underlay designs of Layer 3 to the edge (access layer) while the overlay handles any Layer 2 extension requirements.
When so much effort and pressure are put on designing and implementing strong technology solutions, in my opinion, it’s easy to neglect having visibility into those solutions once they are implemented. While competent design and implementation are important, having access to insight and analytics into the system once the design is in production is just as important. Having a competent design to reduce issues is ideal, but what do you do when the system is not working properly or someone is accusing the system of not functioning properly? Visibility and analytics are important for many reasons, but to me, a big one is troubleshooting. I want to be able to help people resolve issues in the quickest way possible and if I have that deep visibility at the ready, there is a better chance that I can do just that. A more selfish way to put it is “mean time to innocence”. How do I quickly prove or disprove that an issue is my fault so that I can move onto the next task or project? Having visibility, analytics, insight, evidence, etc is key. Whether the system you are designing and implementing has built-in visibility, there is a product out there that can provide that visibility, or you can develop a home-grown solution, leveraging that insight is important. Once the design/solution has been implemented, someone has to support it, and having proper tools can help greatly.
[Factinion Definition: A combination of facts (or at least statements that I believe to be facts) along with my opinions (with which you may agree or disagree).
Background: I am currently on the new CCNP track. One topic that is covered in my studies is Multiple Spanning Tree Protocol. MSTP is something that I’ve seen in the CLI, but never delved into until now. In this post, I’ll go over my understanding of the protocol as well as deliver my opinion. This post can be seen as “high level” and not getting in depth into the protocol in question. I encourage you to comment with your thoughts and to let me know where I got it wrong.
The Need for MSTP: Rapid Per VLAN Spanning Tree (PVST+) gives us the ability to maintain a separate Spanning Tree instance for each VLAN in our environment. In a traditional Layer 2 topology where we have multiple access layer switches that are dual connected to diverse distribution layer switches, leveraging PVST+ allows us to “load balance” VLANs to either distribution layer switch #1 or #2 by alternating forwarding and blocking ports on the different access layer switches. One thought is to have all odd numbered VLANs actively forward to distribution layer switch #1 and all even numbered VLANs actively forward to distribution switch #2. While this practice is valid, it may not scale well. A separate Spanning Tree is maintained for each VLAN and separate BPDUs need to be generated and processed for each VLAN. That could become resource intensive for switches as “many” VLANs are added to the topology. Enter MSTP as a scalability option.
My Understanding of MSTP: MSTP builds off of the PVST+ protocol. We can still achieve the load balancing goal explained above, while minimizing the number of Spanning Tree instances. For example, let’s say we have 20 VLANs in our topology. With PVST+, we would have 20 instances of Spanning Tree running. If we wanted to load balance VLANs across the two distribution switches, we could leverage MSTP and cut the number of instances down to 2. MSTP allows us to group multiple VLANs into a single instance. Building off of our load balancing example, we could have odd numbered VLANs in instance #1 (with distribution switch #1 as the root bridge) and even numbered VLANs in instance #2 (with distribution switch #2 as the root bridge). Any VLANs not specified to a given instance would automatically be joined to the Internal Spanning Tree instance (instance 0).
My Opinion: While I see the place and benefit for MSTP, it also adds a level of complexity that needs to be considered. Certain parameters need to match across switches in the topology, and because of this I can see where it could become difficult to manage and troubleshoot. On another note, outside of the individual Spanning Tree modes, I can see STP altogether becoming less relevant. With Software Defined everything, overlays are bridging the Layer 2 gap over end to end Layer 3 networks. Large native Layer 2 domains can become very complex and difficult to troubleshoot. While STP does its job well, if Layer 3 can be taken as far to the edge as possible, minimizing STP domains and calculations, that makes sense to me to do so. However, if Layer 2 from the distribution layer to the access layer is necessary, there are Cisco technologies such as Virtual Switching System (VSS) and StackWise Virtual in the Catalyst line, and virtual PortChannel (vPC) in the Nexus line to make that more efficient. With these technologies, the physically diverse distribution switches can be paired together to appear as a single logical switch to the access layer.