Worth Reading: BGP in 2016

Figure 2 illustrates an important principle in BGP, that there is no single authoritative view of the routing table – all views are in fact relative to the perspective of the BGP speaker. It also illustrates that at times the cause of changes in routing is not necessarily a change at the point of origination of the route which would be visible to all BGP speakers across the entire Internet, but it may well be a change in transit arrangements within the interior of the network that may expose, or hide, collections of routes. And thirdly, this illustrates the prevalent use of more specifics to affect traffic engineering. It is often the case that these more specifics are advertised with a limited scope, and if the changes to the transit arrangements move a BGP speaker in or out of this scope, then one can expect changes in the set of visible routes as a consequence. —Potaroo

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RTGWG Interim Meeting on Data Center Challenges

Last week, the Routing Area Working Group (IETF) held an interim meeting on challenges and (potential) solutions to large scale data center fabric design. I’ve filed this here because I spoke for all of about 3 minutes out of the entire meeting—but I really wanted to highlight this meeting, as it will be of interest to just about every network engineer “out there” who deals with data center design at all.

There are three key URLs for the interim

The agenda
The session slides and links to drafts presented
A Webex recording of the entire proceedings

My reaction, in general, is that we are starting to really understand the challenges in a networking way, rather than just as a coding problem, or a “wow, that’s really big.” I’m not certain we are heading down the right path in all areas; I am becoming more convinced than ever that the true path to scale is to layer the control plane in ways we are not doing today. You can see this in the LinkedIn presentation, which Shawn and I shared. I tend to think the move towards sucking every bit of state possible out of the control plane is a Continue reading

Worth Reading: The CCDE “aha” moment

The problem with my mindset was this need to ‘jump to conclusions’, and the core of my issues with being successful with the CCDE practical exam. Hello, I’m Zig the preconceived notion guy! I will forever be known in our CCDE Study group as the preconceived notion guy! Leave your preconceived notions at the door! I cannot emphasize enough how important this is. Bring all of your technical experience and understanding, but leave every other attribute that’s not related to the technology at the door. The scenario will be feeding you all of the information you need to make a valid decision. Your personal experience and opinion about a technology that isn’t technical will only get in your way, as it was in my way. —Cisco Learning

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Worth Reading: An infrastructure for on demand service profiling

LinkedIn has built hundreds of application services, with thousands of instances running in data centers. Optimizing the performance of these services can dramatically improve user experience and reduce operational costs, and profilers are commonly used to help achieve this. LinkedIn’s On-Demand Profiling infrastructure (“ODP”) is one method we use to identify these optimizations. Profiling is a useful method to improve the performance of services. However, the tooling solutions for profiling don’t have fixed standards, are often decentralized, can be costly, and for a company with a large server footprint such as LinkedIn, are inconvenient to use at best. —Linkedin Engineering Blog

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Toxic Cultures and Reality

I have lived through multiple toxic cultures in my life. It’s easy to say, “just quit,” or “just go to HR,” but—for various reasons—these are not always a good solution. For instance, if you are in the military, “just quit” is not, precisely, an option. So how should you deal with these sorts of bad situations?

Start here: you are not going to change the culture. Just like I tell my daughters not to date guys so they can “fix” them, I have never seen anyone “fix” a culture through any sort of “mass action.” You are not going to “win” by going to the boss, or by getting someone from the outside to force everyone to change. You are not going to change the culture by griping about it. Believe me, I’ve tried all these things. They don’t (really) work.

Given these points, what can you do?

Start with a large dose of humility. First, you are probably a part of a number of toxic cultures yourself, and you probably even contribute at least some amount of the poison. Second, you are almost always limited in your power to change things; your influence, no matter how right you Continue reading

Worth Reading: The CCDE Mindset

Preparing for the CCDE from a technology standpoint is relatively easy compared to getting into the right mindset and getting enough exposure to network designs. Don’t get me wrong, it’s a technically difficult exam but the number of candidates taking the exam that have the right knowledge level of technology are far higher than the number of people actually passing the exam. I have seen this time and time again. Because we have this bias we immediately base our feeling and design based on our feelings or previous experience without taking the business requirements and technical constraints into consideration. —Daniel’s Networking Blog

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Worth Reading: IOS/XR in GNS3

Cisco IOS XRv is one of the most popular platforms among network engineers. However, this platform is only available in high-end devices, which might not be available to all engineers. For this reason, engineers prefer to virtualize the OS and GNS3 is one of the most popular network simulators to do this. GNS3 is based on Dynamips, Pemu/Qemu and Dynagen. Simulating Cisco IOS in GNS3 is pretty straightforward. Simulating the XR platform is not. But with new XRv image and a few tweaks, you can now run Cisco XR platform in GNS3. —APNIC

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Tile Roof

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Worth Reading: Innovation at CIDR 2017

Last week was CIDR 2017, the biennial Conference on Innovative Data Systems Research. CIDR encourages authors to take a whole system perspective and especially values “innovation, experience-based insight, and vision.” That’s a very good match with the attributes of papers I like to cover on The Morning Paper. So what innovation, insight, and vision does CIDR have to offer us to see us through until the next edition in 2019? —The Morning Paper

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Worth Reading: IPv6 server addressing strategies

In this post, I’ll discuss configuration approaches for systems that usually have been configured with “static” IP parameters in the IPv4 age/context (for example, servers in data centres). When it comes to IPv6 there are more options and we’ll have a look at their implications and potential advantages/disadvantages. —APNIC

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On the ‘net: Considerations in Moving to an SDDC

There are two basic models to consider when moving data centers: running the old and new in parallel during some form of transition phase, or integrating your existing equipment with the newer SDDC. The second, integrating existing equipment within a single data center fabric, is not one, but two answers: integrating at the pod level, or running the SDDC over the top of existing equipment. —Tech Target

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Worth Reading: Every day is Monday in Operations

If Operations fails, so does your company—it is, as you might say, mission-critical. The delicate trust a company holds with its customers can be shattered by a single sustained outage. Just look at one outage from 2012 which cost millions of dollars per minute while a bug was in production. When a major incident occurs, no customer cares about who was at fault, the extenuating circumstances, or how you’re going to do better next time. They leave, wondering why they trusted your company in the first place. In Operations, failure is not an option. —LinkedIn Engineering

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Worth Reading: Windows 10 steps up ransomware defenses

Here’s some good news for the countless businesses getting ready for the migration to Windows 10: Microsoft recently announced that its Windows 10 Anniversary Update features security updates specifically targeted to fight ransomware. No defense is completely hack-proof, but it’s great to see the biggest names in the tech world are putting ransomware at the top of their list of concerns. —Cloud Security Alliance

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OSPF TLVs: Taking advantage of improvements in computing power

OSPF was originally designed in an age when processors were much less capable, available memory was much smaller, and link bandwidths were much lower. To conserve processing power, memory, and n-the-wire bandwidth, OSPF was designed using fixed length fields (FLFs). TLVs are more difficult to process than an FLF; to process a set of FLFs, you build a structure that mimics the FLF formatting, and simple “impose” it on the memory location where you have stored the data to be decoded, as shown below.

In the FLF model, the structure can simply be imposed on the memory locations, and the values can be read directly. In the TLV model, each type code must be read to determine the kind of information and the length must be read to determine the size of the field. Only once these two items in the TLV header have been read can the actual data be related to a particular field in the resulting data structure.

In the intervening years, however, compute, storage, and network capabilities have increased dramatically; the following chart, taken from a book I’m working on, shows this growth since about the start of the “network era.”

As compute, storage, and Continue reading

Worth Reading: Fix EULAs

Traditionally, once a person has purchased a product, she has been free to use it however she sees fit without oversight or control from the copyright owner. Purchasers have also been free to use competitors’ add-on software and hardware that interoperate with the goods they buy, because innovators have been able to develop and distribute such technologies. That expectation is upended when it comes to products that come with embedded software, from tractors to refrigerators to toasters and children’s toys. That software is supposed to make our stuff smarter, but it also makes our stuff not really ours. —EFF

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Worth Reading: Internet routing detours

In November 2013, the Internet intelligence company Renesys (now owned by Dyn, Oracle) published an online article detailing an attack they called Targeted Internet Traffic Misdirection. Using Traceroute data, they discovered three paths that suffered a man-in-the-middle (MITM) attack. One path originated from, and was destined to, organizations in Denver, CO, after passing through Iceland, prompting concern and uncomfortable discussions with ISP customers. Are such detours only a result of an attack? —APNIC

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Updated Generic Icon Set

I’ve updated the generic icons linked from this page to include a virtual router/switch. I’ve also added two different spine and leaf topologies to the presentation. I may add other “generic” topologies over time, as I run across ones that seem worth including. These are completely public domain; I would encourage you to use them instead of the normal sets of vendor icons in drawing, books, blogs, etc.

Updated: Thanks to Greg Ferro, there is now a version of these in Omnigraffle! They’re linked on the same page.

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On the ‘net: The background of I2RS

Through this (probably far too long) series on SDNs, we have looked at BGP, Fibbing, and Openflow. BGP and Fibbing would be described as augmented control planes; the distributed control plane is not replaced, but rather augmented with a controller that modifies the best path decisions of the control plane by interacting with the control itself in a somewhat “native” way. Openflow, on the other hand, replaces the distributed control plane; it would actually be difficult to build a system that talks directly to the FIB that does not entirely replace the control plane. But in the original classification, there was a third type of SDN highlighted, a hybrid model. Are there any instances of this sort of model being developed? —ECI Blog

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Worth Reading: Study highlights lack of IoT security

Despite widespread concern about the security of mobile and Internet of Things (IoT) applications, organizations are ill-prepared for the risks they pose, according to a research report issued today from Ponemon Institute, IBM Security, and Arxan Technologies. “Mobile and IoT applications continue to be released at a rapid pace to meet user demand. If security isn’t designed into these apps there could be significant negative impacts,” says Diana Kelley, Global Executive Security Advisor, IBM Security. —Circle ID

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Worth Reading: Videos from ION Bucharest

We held ION Bucharest last year alongside the Romanian Network Operators’ Group (RONOG). It took a little longer than usual, but now all the presentations and video archives are available online. As we gear up for ION Islamabad next week on 25 January, this is a chance to get a sneak peak at the type of content we’ll be presenting! Bucharest was filled with IPv6, DNSSEC, DANE, TLS, IETF, and Routing Security information, and now you can watch it all from the comfort of your own device. —The Internet Society

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