Why is the Feasibility Condition Less Than?

A reader recently emailed me with this question: Why isn’t the condition for a Feasible Successor set to less than (<), rather than less than of equal (<=), in EIGRP? It certainly seems, as noted in the email, that this rules out a lot of possible possible loop free alternate paths. The network below will be used to illustrate.

First, assume all links are cost of 1 except D->C, which is cost of 2. Here D will choose B as the Successor, and the FC will be set to 2. The RD of C will be 1, so C will be an FS. Now consider two failures. The first failure is D->B. D will immediately reroute to the FS, which is C, without changing the FC. This works, because C’s cost to 100::/64 via D is 4, much higher than it’s cost to 100::64 along C->A. Now consider what happens if A->100::/64 fails. If the timing of the query “works right,” C and B will be notified first, then finally D. Even if D is somehow notified before C, and D switches to C as its FS, the traffic is dropped, rather than looped—so all is happy.

Now change the situation a little. Assume the A->C link is cost Continue reading

Tune in to Our Q&A tomorrow!


Don’t miss our CCNA/CCNP Kickoff with Keith Bogart Tomorrow!

 

Join Keith May 8th at 10 am PST/ 1 pm EST for his CCNA/CCNP Kickoff.

This is a FREE live session that is open to everyone. In this open forum, you’ll have the opportunity to ask Keith all of your questions regarding the CCNA or CCNP Routing & Switching exam and related technologies.

Get all of your questions answered by an experienced industry expert! Just click here.

Enterprises are moving SD-WAN beyond pilot stages to deployment

Research conducted by market research firm IHS Markit found that 74 percent of firms surveyed had SD-WAN lab trials in 2017, and many of them plan to move into production this year.The report, titled “The WAN Strategies North America” (pdf, registration required), found security is the number one network concern by a wide margin and the top reason to invest in new infrastructure, as companies must fend off the constant threat of cyber attacks.There are other reasons, as well, such as traffic growth, company expansion, adoption of the Internet of things (IoT), the need for greater control over the WAN, and the need to put WAN costs on a sustainable path.To read this article in full, please click here

Enterprises are moving SD-WAN beyond pilot stages to deployment

Research conducted by market research firm IHS Markit found that 74 percent of firms surveyed had SD-WAN lab trials in 2017, and many of them plan to move into production this year.The report, titled “The WAN Strategies North America” (pdf, registration required), found security is the number one network concern by a wide margin and the top reason to invest in new infrastructure, as companies must fend off the constant threat of cyber attacks.There are other reasons, as well, such as traffic growth, company expansion, adoption of the Internet of things (IoT), the need for greater control over the WAN, and the need to put WAN costs on a sustainable path.To read this article in full, please click here

Successful Machine Learning With A Global Data Fabric

One of the most common misconceptions about machine learning is that success is solely due to its dynamic algorithms. In reality, the learning potential of those algorithms and their models are driven by the data preparation, staging and delivery. When suitably fed, machine learning algorithms work wonders. Their success, however, is ultimately rooted in the data logistics.

Data logistics are integral to how sufficient training data is accessed. They determine how easily new models are deployed. They specify how changes in data content can be isolated to compare models. And, they facilitate how multiple models are effectively used as part

Successful Machine Learning With A Global Data Fabric was written by Timothy Prickett Morgan at The Next Platform.

Network Break 183: VMware Embraces Cloud Networking; Cisco Acquires Accompany

Take a Network Break! VMware announces its Virtual Cloud Network vision and outlines the product portfolio to bring that vision to life. Dell Technology World showcases new servers and storage and cements Dell’s one-stop-shop strategy. Cisco spends $270 million to buy relationship intelligence purveyor Accompany.

Cisco also shed its service provider video business, Anuta Networks makes its orchestration platform available as SaaS, and the Lojack laptop recovery software suffers a serious vulnerability.

Meanwhile, a Webex vulnerability enables remote code execution, Arista shares dip despite a strong quarter, and Juniper shares rise slightly despite a poor one.

Get links to all these stories after our sponsor message.

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Show Links:

VMware Advances Networking for the Digital Era with the Virtual Cloud Network – VMware

Dell outlines a one-stop-shopping portfolio for technology-hungry businesses – Diginomica

Cisco Announces Intent to Acquire Accompany – Cisco

Permira Funds to Acquire Cisco’s SPVSS Business – Cisco

Continue reading

Hybrid Operations with Ansible

RedHat-Summt-2018-Blog

Hybrid Operations with Ansible

One of the most common questions I hear while talking about Ansible's support for cloud providers is whether it will work in hybrid environments. You may not be able to use the ec2 module to create an instance in your datacenter, but Ansible has modules for RHV, OpenStack, and VMWare to talk to virtualization tools in your datacenter. I love working in AWS, Azure, and Google Cloud but most environments I've worked in have had on-prem systems as well.

That's what I've been invited to Red Hat Summit to talk about -- best practices for automating all the infrastructure at your disposal, not just the cloud services. My demos will feature a couple new Ansible Core/Engine 2.5 features, as well as preview new 2.6-only features.

My favorite feature to show off is part of the new ec2_instance module. In the demo we'll have a look at how Tower provisioning callbacks are now built in to the ec2_instance module, making provisioning brand new instances as easy as:

- ec2_instance:
  image:
    id: "{{ latest_centos.image_id }}"
  key_name: my-secret-key
  instance_type: t2.large
  name: call-me-maybe
  security_groups:
    - demo-web-sg
  # COOL MAGIC HERE
  tower_callback:
    host_config_key: "{{ your_secret_here }}"
    job_template_id:  Continue reading

Fabrics Open The Way For Storage Class Memory

Dell EMC has long been a vocal proponent of NVM-Express, the up and coming protocol that cuts out the CPU jib-jab with PCI-Express peripherals and that boost throughput and drops latency for flash and other non-volatile memory.

For the past two years, Dell, like other system makers, has put NVM-Express drives in its servers while ramping up the flash in its high-end storage systems and preparing to bring the protocol to those external storage appliances. It has taken time to get the arrays reworked, for the price of NVM-Express drives to come down, and for the volumes to ramp up.

Fabrics Open The Way For Storage Class Memory was written by Jeffrey Burt at The Next Platform.

What is BGP Hijacking, Anyway?

Two weeks ago, we learned about yet another routing security incident, namely the hijack of BGP routes to the Amazon DNS infrastructure, used as a stepping stone to steal about $150,000 of Ethereum cryptocurrency from MyEtherWallet.com. We’ve been talking a lot lately about BGP hijacking, digging into the details of what happened in this post. But maybe we need to back up a minute and answer: What in the world is BGP hijacking, anyway, and why does it matter? Here, we’ll explain the basics and how network operators and Internet Exchange Points can join MANRS to help solve the problem.

What is BGP?

BGP, or Border Gateway Protocol, is used to direct traffic across the Internet. Networks use BGP to exchange “reachability information” – networks they know how to get to. Any network that is connected to the Internet eventually relies on BGP to reach other networks.

What is BGP Hijacking?

In short, BGP hijacking is when an attacker disguises itself as another network; it announces network prefixes belonging to another network as if those prefixes are theirs. If this false information is accepted by neighboring networks and propagated further using BGP, it distorts the “roadmap” of the Continue reading

The Week in Internet News: Criminal Cryptocurrency Miners Target IoT

Cryptomining the IoT: Cryptocurrency mining has caused a run on high-powered graphics cards, but criminal groups are looking for ways to exploit other computing power for mining operations. One target is Internet of Things networks because of the lack of strong security on many IoT devices, reports ZDNet. IoT cryptojacking malware is becoming popular on underground forums.

Secrecy for Slackers: Have you ever sent a message on Slack that you didn’t want your boss to see? Or maybe you’re concerned that someone could forward your Slack conversations. Apparently, you’re not alone. Security consulting firm Minded Security has created a tool, called Shhlack, that allows for encrypted messages in the popular messaging app, Motherboard says.

Hey, something worked! Law enforcement authorities in several countries worked together to take down WebStresser, a large DDoS-for-hire service, in late April. In the week following the takedown, DDoS attacks observed by one security provider dropped by about 60 percent in Europe, BleepingComputer reports.  The drop may have been only temporary, however.

Fake news hits the courts: Malaysia’s controversial new has its first casualties. A Danish citizen has pleaded guilty maliciously publishing a fake news report by posting a YouTube video that appeared to contradict Continue reading

HPE’s new Nimble flash arrays offer storage guarantee, NVMe and SCM support

HPE is rolling out the next generation of its Nimble Storage platform, overhauled to better meet the ever-increasing performance demands on data-center workloads, including real-time web analytics, business intelligence, and mission-critical enterprise resource applications.The new HPE Nimble Storage All Flash arrays as well as Nimble Adaptive Flash arrays for hybrid implementations (mixing solid state drives and hard disk drives, for example), are generally available from May 7 and have both been engineered to support NVMe (non-volatile memory express), an extremely fast communications protocol and controller designed to move data to and from SSDs via the PCIe bus standard. NVMe SSDs are expected to offer two orders of magnitude speed improvement over prior SSDs.To read this article in full, please click here

HPE’s new Nimble flash arrays offer storage guarantee, NVMe and SCM support

HPE is rolling out the next generation of its Nimble Storage platform, overhauled to better meet the ever-increasing performance demands on data-center workloads, including real-time web analytics, business intelligence, and mission-critical enterprise resource applications.The new HPE Nimble Storage All Flash arrays as well as Nimble Adaptive Flash arrays for hybrid implementations (mixing solid state drives and hard disk drives, for example), are generally available from May 7 and have both been engineered to support NVMe (non-volatile memory express), an extremely fast communications protocol and controller designed to move data to and from SSDs via the PCIe bus standard. NVMe SSDs are expected to offer two orders of magnitude speed improvement over prior SSDs.To read this article in full, please click here

HPE’s new Nimble flash arrays offer storage guarantee, NVMe and SCM support

HPE is rolling out the next generation of its Nimble Storage platform, overhauled to better meet the ever-increasing performance demands on data-center workloads, including real-time web analytics, business intelligence, and mission-critical enterprise resource applications.The new HPE Nimble Storage All Flash arrays as well as Nimble Adaptive Flash arrays for hybrid implementations (mixing solid state drives and hard disk drives, for example), are generally available from May 7 and have both been engineered to support NVMe (non-volatile memory express), an extremely fast communications protocol and controller designed to move data to and from SSDs via the PCIe bus standard. NVMe SSDs are expected to offer two orders of magnitude speed improvement over prior SSDs.To read this article in full, please click here

Using 4-Byte BGP AS Numbers with EVPN on Junos

After documenting the basic challenges of using EBGP and 4-byte AS numbers with EVPN automatic route targets, I asked my friends working for various vendors how their implementation solves these challenges. This is what Krzysztof Szarkowicz sent me on specifics of Junos implementation:

To learn more about EVPN technology and its use in data center fabrics, watch the EVPN Technical Deep Dive webinar.

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