One of the most asked questions which come up in the xISP world is “How do I learn this stuff?”. Depending on who you ask this could be a lengthy answer or a simple one-sentence answer. Before we answer the question, let’s dive into why the answer is complicated.
In many enterprise environments, there is usually pretty standard deployment of networking hardware. Typically this is from a certain vendor. There are many factors involved. in why this is. The first is the total Cost of Ownership (TCO). It almost always costs less to support one product than to support multiples. Things like staff training are usually a big factor. If you are running Cisco it’s cheaper to train and keep updated on just Cisco rather than Cisco and another vendor.
Another factor involved is the economies of scale. Buying all your gear from a certain vendor allows you to leverage buying power. Quantity discounts in other words. You can commit to buying a product over time or all at once.
So, to answer this question in simple terms. If your network runs Mikrotik, go to a Mikrotik training course. If you run Ubiquiti go to a Ubiquiti training class.
Now that the simple question has been answered, let’s move on to the complicated, and typically the real world answer and scenario. Many of our xISP clients have gear from several vendors deployed. They may have several different kinds of Wireless systems, a switch solution, a router solution, and different pieces in-between. So where does a person start?
I recommend the following path. You can tweak this a little based on your learning style, skill level, and the gear you want to learn.
1. Start with the Cisco Certified Network Associate (CCNA) certification in Routing and Switching (R&S). There are a ton of ways to study for this certification. There are Bootcamps (not a huge fan of these for learning), iPhone and Android Apps (again these are more focused on getting the cert), online, books, and even youtube videos. Through the process of
studying for this certification, you will learn many things that will carry over to any vendor. Things like subnetting, differences between broadcast and collision domains, and even some IPV6 in the newest tracks. During the course of studying you will learn, and then reinforce that through practice tests and such. Don’t necessarily focus on the goal of passing the test, focus on the content of the material. I used to work with a guy who went into every test with the goal of passing at 100%. This meant he had to know the material. CompTIA is a side path to the Cisco CCNA. For reasons explained later, COMPTIA Network+ doesn’t necessarily work into my plan, especially when it comes to #3. I would recommend COMPTIA if you have never taken a certification test before.
2. Once you have the CCNA under your belt, take a course in a vendor you will be working
the most with. At the end of this article, I am going to add links to some of the popular vendor certifications and then 3rd party folks who teach classes. One of the advantages of a 3rd party teacher is they are able to apply this to your real-world needs. If you are running Mikrotik, take a class in that. Let the certification be a by-product of that class.
3.Once you have completed #1 and #2 under your belt go back to Cisco for their Cisco Certifed Design Associate (CCDA). This is a very crucial step those on a learning path overlook. Think of your networking knowledge as your end goal is to be able to build a house. Steps one and two have given you general knowledge, you can now use tools, do some basic configuration. But you can’t build a house without knowing what is involved in designing foundations, what materials you need to use, how to compact the soil, etc. Network design is no different. These are not things you can read in a manual on how to use the tool. They also are not tool-specific. Some of the things in the Cisco CCDA will be specific to Cisco, but overall it is a general learning track. Just follow my philosophy in relationship to #1. Focus on the material.
Once you have all of this under your belt look into pulling in pieces of other knowledge. Understanding what is going on is key to your success. If you understand what goes on with an IP packet, learning tools like Wireshark will be easier. As you progress let things grow organically from this point. Adding equipment in from a Vendor? Update your knowledge or press the new vendor for training options. Branch out into some other areas , such as security, to add to your overall understanding.
WISP Based Traning Folks.
These companies and individuals provide WISP based training. Some of it is vendor focused. Some are not. My advice is to ask questions. See if they are a fit for what your goals are.
If you provide training let me know and I will add you to this list.
As Internet traffic grows and becomes more dynamic, optical transport networks for sub-sea, terrestrial long haul and metro need more capacity. The ability to deploy capacity quickly is equally important to handle the increasingly dynamic nature of the traffic. The concept of a multi-haul transport platform, as introduced by Andrew Schmitt of Cignal AI, becomes very appealing for achieving this ability to scale with speed while maintaining operational simplicity – a single platform for all requirements. A critical element of the multi-haul optical platform is the flexibility of the coherent optics to be tuned to fine granularity in order to meet the reach-capacity target of any given network.
While double checking some stats on a network I came across this in Libre. 84% is usually something that would cause me to be alarmed, as Libre is trying to tell us.
After some research, I found the following.
While it is not documented, it was noted that this was by design and that it would not affect the switch as the switchport becomes more and more loaded.
The switch allocates dedicated memory to certain processes / resources by default and then additional resources when the configuration is added. This ensures proper functionality and is again by design.
The I/O Memory pool buffers information transmitted to and from the CPU, and does not affect the actual forwarding of packets on the switch.
Translation: The switch uses up these resources by default, even if they aren’t all being used. Think of it as setting it aside for future use without dynamic allocation of them.
Outbound Route Filtering (ORF) is a Cisco proprietary feature that prevents the unnecessary exchanging of routes that are subject to inbound filtering. This, in turn, minimizes bandwidth across the links and reduces CPU cycles upon the router during the processing of the neighbor UPDATE.
ORF works by the router transmitting its inbound filters to its neighbor, which the neighboring router then applies outbound.
great article on how to do this if you are running Cisco routers and your provider is too.
At 00:00 on 1 Jan 2020 UTC, all Self-Signed Certificates (SSC) that were generated on IOS/IOS-XE systems will expire, unless the system was running a fixed version of IOS/IOS-XE when the SSC was generated. After that time, unfixed IOS systems will be unable to generate new SSCs. Any service that relies on these self-signed certificates to establish or terminate a secure connection might not work after the certificate expires.
I had a good discussion with my Buddy JJ tonight on kind of the next step of network evolution for provider networks. Many providers have evolved to MPLS networks with VPLS. There are some inherent issues with this when it comes to things like bonding, MLAG, among other issues. Nothing is perfect, right?
So as we dive into What is EVPN I want you to know I am approaching this from a service provider standpoint. I also am no EVPN expert, but I am seeing it more and more as a solution to solve specific issues. As a result, EVPN is sliding into a natural progression of the service provider network.
So what is EVPN?
There are folks much more versed on EVPN than I am. As a result, I will lean on some already written articles.
Components of EVPN
Now that you have a high-level overview of EVPN, what are some of the major components and features you should know? Let’s dive into that
Unified control plane. EVPN can be used throughout your network. You don’t have to use one stack for data center, one for metro to the data center, and yet another for connectivity between data centers. You can bring it all under one control roof so to speak.
EVPN, through BGP, marries the Layer 2 and Layer 3 layers together. With MPLS everything is controlled at the layer3 level. Now with EVPN Mac addresses become much more important. For example, Each EVPN MAC route announces the customer MAC address and the Ethernet segment associated with the port where the MAC was learned from and is associated MPLS label. This EVPN MPLS label is used later by remote PEs when sending traffic destined to the advertised MAC address. Pretty cool huh?
As networks grow network engineers learn about things such as north-south traffic and east-west traffic. Microsoft has a great article which explains this concept. https://blogs.technet.microsoft.com/tip_of_the_day/2016/06/29/tip-of-the-day-demystifying-software-defined-networking-terms-the-cloud-compass-sdn-data-flows/
East-West – East-West refers to traffic flows that occur between devices within a datacenter. During convergence for example, routers exchange table information to ensure they have the same information about the internetwork in which they operate. Another example are switches, which can exchange spanning-tree information to prevent network loops.
North | South – North- South refers to traffic flows into and out of the datacenter. Traffic entering the datacenter through perimeter network devices is said to be southbound. Traffic exiting via the perimeter network devices is said to be northbound.
So, if you are a growing Service provider look at EVPN. In some upcoming articles, I will talk more about various components of EVPN and such.