Rapidly Evolving Technologies: What You Know versus What You Need to Study

Throughout their careers as network professionals, individuals must learn new concepts, tools, and solutions to solve various technical and operational challenges and continue growing well technically and with pleasing results on their journey in this area. From time to time, classic and established technologies and tools become "obsolete" and replaced by new tools, technologies, and solutions to solve - for the most part - the very same old challenges.

Even with simple things such as "carrying L2 and L3 services throughout their networks". After all, what's so complicated about passing VLANs and IP subnets back and forth? No biggie, right? These L2 and L3 things have been around for decades, and we're all used to dealing with these realities. Well, think carefully.

If we look at it more thoroughly, there are several ways to enable the transportation of L2 and L3 services in computer networks, and there are significant differences between the options and scenarios, from the components used, their respective functional principles, the operational issues, support, and verification; concepts related to the availability and capacity of these resources, and so on. Not to mention that there are due "pros" and "cons" for each form or method, right? Each scenario or option considered to enable the transport of an L2 or L3 service has its challenges, limitations, and restrictions. More experienced professionals are bare to hear or know terms like scalability, reliability, resiliency, performance, availability, interoperability, capacity, security, usability, manageability, among others.?

And each of these functional towers from a technical project can be expanded into a very long discourse of active adhesions and deviations, in the best case-by-case style.

No, there is no need to technically discuss here the differences among "hundreds" of primary and peripheral technologies that we can enable to transport these L2 and L3 services. That's because it is not the focus of this article to talk about what those technologies do and how they work, but to register or list some of these situations so that you have a sense of where you are currently and in which direction you will need to sail - that is, assuming here that you want to be a computer networking expert! :-)

More than ever, it is crucial for professionals to stay tuned in to everything around them in this area, mainly involving technologies, solutions, tools, processes, and best current operational practices that are part of their daily reality. Again, there are several available tools and scenario options that we can marshal to solve technical and operational issues that are important to the business or for whatever KPI or CSF indexes are relevant to the company. Such hurdles require awareness and the accurate application of many networking technologies. For every form or method, there are gains and losses: the good and the bad.

There are powerful or minimalist results, depending on what one chooses for the technical design, and the same applies to restrictions and limitations. Technologies/tools do not work miracles and are not born alone in the running configuration of your network devices: all this must be managed by you, the network professional. You'll have to design, deploy, operate and support it all whenever you are required to do those tasks. Things can go wrong; the predictability of your network's traffic flows can go awry and cause tremendous headaches. A more severe failure can be disastrous for your mental health (acting under pressure). And this includes communication link failures or device failures, incidents caused by limitations in the functionalities or resources used, insufficient resources and capacities, incidents arising from human error (you or someone), accidental or negligent non-compliance practices, and highly complex security incidents, among many other events and circumstances.

I am returning to my line of reasoning here. Understanding the functioning of L2 and L3 technologies, from their respective origins and most fundamental concepts, contributes relentlessly so that the professional can continue to grasp new technologies, trends, and tools to overcome the technical challenges of everyday projects and operations. The broader the perception, understanding, and grasp of these fundamentals, the better you do this homework of "learning the basics and well done," the easier it will be for you to digest new trends, arguably more sophisticated and complex in point of view of knowing and deploying. The following observation of mine is even more interesting:

The better and broader one technology proposal is to simplify and solve the technical and operational challenges of the company's networks or the business itself, the more complex this technology will usually be in terms of learning, blending, and adoption by computer networking professionals. How delightful!

Can I give you some advice? Honest and friendly advice. Don't rush into MPLS-based technologies or anything like that if you are still far from mastering the workings of routing and switching architectures and the very foundation of?IPv4 and IPv6 protocols and related basics. You don't want to dig too deep into traditional L2VPN technologies if you're far from fully understanding the workings of tunnels, pseudowires, and even the basics of how classic switching architectures and Ethernet resiliency protocols work. Aspiring to be a BGP routing protocol expert without knowing how to expound, implement and support networks powered by Link-State interior gateway routing protocols (OSPF, ISIS) is somewhat counterproductive, as one thing depends so closely on the other! You see, this is not a criticism, and I'm not suggesting that you shouldn't be interested in or study these examples mentioned above: what happens is that there is an indicated or structured learning order so that things can fit together in a perfectly balanced way back in the corner of your brain.

Don't skip stages!

Concentrate on absorbing well what's underneath everything, start from the very basics, and keep evolving with fitted studies to continue expanding your container of knowledge and skills.

I was thinking here and exemplifying the evolutions of technologies that can transport L2 and L3 services over converged, highly resilient, scalable, elastic, and dynamic infrastructures. Examples of technologies and practices embedded in large network operators' logical projects, particularly in parts or perimeters of the network where Metro/IP/MPLS architectures and Carrier Ethernet standards are present. And using one of my previous workshops as a reference for discussions and practices of these technologies. Let's see what this workshop, called "Carrier Ethernet Technologies Workshop: L2 and L3 Unicast and Multicast Services Transport on Next-Generation Metro and MPLS Networks" covers:

• Flexible Ethernet edge and access (Flexible VLAN Tagging); MPLS LDP enabled infrastructure between edge and backbone perimeters; RSVP-TE in the Core along with Fast Reroute (FRR) and DiffServ-Aware (DS-TE) via Russian Dolls Bandwidth Constraints Model (RDM), but accommodating LDP Tunneling between edge routers. Technologies that have been on the market for quite a long time but have reached an incredible degree of maturity and are not likely to be replaced anytime soon.
• The "classic" MPLS won't die anytime quickly because Segment Routing / SRv6 has emerged! SRTILFA and SR-TE won't replace traditional RSVP-TE designs overnight; you can bet on that, even with the innovations introduced by BGP-LS and BGP Dynamic SR-TE. This reality will happen relatively slowly also gradually, but it is good to follow and specialize in these topics.
• Unified MPLS is complex but still a mature design approach for massively scalable networks. We will soon be moving on to newer design options from there.
• As far as the carrier's corporate subscriber products and services go, Internet in combination with VPNv4 and VPNv6 services, transported over a BGP-Free plus RSVP-TE core perimeter, and IPv6 service transport over IPv4 sessions between edge and Route Reflector Clusters, that is, with the benefit of IPv6 Provider Edge over MPLS (6PE/6VPE). Let's see, BGP-Free Core is an approach and not a specific technology, and it's been around for many years, and it's not going to be discontinued. Quite the opposite. At least for now. As for the 6PE, although all modern routers don't have the slightest problem in dealing with IPv6, many operators would love to keep their backbones on 6PE/6VPE for several reasons. And with the increase of more and more projects involving multiple BGP address families, more and more platforms are dedicated to route reflector functions only (such as the Juniper JRR200 Route Reflector appliance, Cisco's XRv, and others).
• Various combinations of L2VPN in the same topology as enterprise subscriber products for L2 services over MPLS, even to facilitate the discourse and understanding between their differences, restrictions, limitations, and advantages: VPWS "Kompella" (BGP for AD and signaling), FEC 129 (BGP for autodiscovery/AD and LDP for signaling), and Flow-Aware Transport (FAT) or Entropy Label support for pseudowire-based solutions. Although MPLS-based L2VPN technologies (VPWS, VPLS/H-VPLS) have innovated and solved numerous challenges and overcome several limitations of native L2 networks, the fact is that they introduce their challenges and limitations. Issues that Ethernet VPN (EVPN, BGP AFI 25 SAFI 70) came to solve, so yes, the trend here is to gradually and somewhat rapidly replace these traditional L2VPN designs based on pseudowires to the solutions and innovations offered by the EVPN.
• Data Center interconnections via EVPN-VXLAN-MPLS, where VXLAN is present in the data center's data plane and, in the operator's backbone, the transport is carried out by MPLS instead. It is just one of many scenarios involving EVPN as a control plane protocol unification with BGP. Among so many current and legacy technologies for the extension of L2 services between data centers (dark fiber, OTV, traditional L2VPN...), EVPN, in combination with MPLS and VXLAN, with our without DWDM, is undoubtedly the one that best allows for the construction of legitimate "IP Fabric" bringing all the range of benefits of a technical nature to enrich projects and maximize results. That's what's in fashion right now.
• Redundant BGP Route Reflector Clusters design in the core, or dedicated off-path Route Reflector Clusters, obviously without programming prefixes/NLRIs into the routing tables. The network core or actual backbone is entirely free of BGP routes in the routing tables and forwarding plane structures. A practice that has walked with us for so long and that we all enjoy a lot. Secure, reliable, mature, and standard.
• Routing policies considering RPSL specifications (IRR) + RPKI + IN and OUT designs based on latency metrics and link costs with the proper handling of IN and OUT announcements and respective manipulations of BGP attributes in matching scenarios with Enter-Deep Cache, public and private peering, in addition to IP transit, and customer cone. Routing policies observing hot potato and cold potato BGP scenarios. For starters, the IRR has been around for decades... but only now the smaller Autonomous Systems are chasing it (much due to the large ASNs and, most importantly, many Tier-2 ISPs are now, finally, refusing prefix announcements with IRR inconsistencies). RPKI is another mechanism that has been adopted rapidly by smaller ISPs. There are no other resources available, such as BGPsec, for the time being.
• Configuration of the routing infrastructure to protect the network against attacks launched to the control plane of network equipment, such as routing protocol authentication, firewall filters, and additional security mechanisms for each service or protocol, their tables, and structures.?Among other acceptable tunning strategies.
• BGP routing security with Remote Triggered Black Hole Filtering (RTBH) and DDoS mitigation with BGP Flowspec. RTBH is quite an outdated tool for a start, but it can still be helpful in some cases. Now Flowspec has been a true homeland savior, obviously when combined with DDoS attack mitigation solutions. New security concepts to solve the usual challenges plus the understanding and prevention of unknown and zero-day attack vectors, must always be on the radar of modern and up-to-date networking and ICT professionals.
• Security design of the Autonomous System routing practices according to established industry frameworks, in association with RFC 7454 / BCP 194, BCP 185, BCP 38, and MANRS, and compliance with the recommendations of the associated and complementary RFCs (RFC 1918, RFC 5735, RFC 6598, ASN: RFC 7607, RFC 4893 AS_TRANS, RFC 5398 and documentation/example ASNs, RFC 6996 Private ASNs and RFC IANA reserved ASNs; RFC 4291, RFC 6666, RFC 3849, RFC 1897, RFC 2471, RFC 4843, RFC 5226 and RFC 5180 ).
• Also, seeing BGP PIC and Edge and other control plane and routing security mechanisms, reliability and convergence to maximize the infrastructure reliability, resilience, and high availability indicators. The mix of possibilities here is impressive! Among other technologies, tools, and procedures. We should do our best to extract the most benefits from the tools and technologies at our disposal in our projects involving BGP and other infrastructure technologies.
• Multicast VPN for corporate customers with scenarios such as Draft Rosen (legacy, but still widely used) and NGMVPN.
• Autonomous Systems interconnection for cooperation in the exchange of MPLS-based services (e.g., Inter-AS Option C).

How many of these technologies and concepts, as mentioned earlier, do you know? In terms of analytical and discourse skills, as well as scientific, empirical, and tacit knowledge?

Don't get frustrated if you identify yourself with very little or having a low affinity with these technologies, even though you've been around as a networking professional for quite some time now! Follow my advice: study in an organized and disciplined way. And starting from the very basics, not skipping steps! Do this with dedication, and when you least expect it, you will be dealing with a whole new universe of new technologies and tools that will make much more sense for you to solve your technical projects or daily operation problems. Trust in your potential, believe in your dreams and goals, and keep moving forward!

I will soon be conducting a demonstration of these concepts in videos on my channel. It has a lot of content available already! Take a look there, check the contents, subscribe, and share! @LeonardoFurtadoNYC on YouTube.

In addition, please feel free to interact with me about this article. I look forward to reading your comments!

Thank you! And see you around!

Leonardo Furtado