Response: The OSI Model Is a Lie

Every now and then I stumble upon a blog post saying “OSI 7-layer model sucks” or “OSI 7-layer model is a lie”, most recent one coming from Robert Graham.

Before going into the details, let’s agree on the fundamentals.

Most everyone who ever tried to build a network spanning more than one transmission technology and including intermediate nodes came to the conclusion that layered approach to networking makes sense.

Whether you have three, four, five, or seven layers in your model doesn’t matter. What really matters is that your model contains all the functionality you need to implement host-to-host networking in target environment.

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AT&T’s Debt Lands It in Crosshair of Activist Investor

Elliott Management is targeting the media conglomerate for what it calls “long-term...

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Packet analysis using Docker

Why use sFlow for packet analysis? To rephrase the Heineken slogan, sFlow reaches the parts of the network that other technologies cannot reach. Industry standard sFlow is widely supported by switch vendors, embedding wire-speed packet monitoring throughout the network. With sFlow, any link or group of links can be remotely monitored. The alternative approach of physically attaching a probe to a SPAN/Mirror port is becoming much less feasible with increasing network sizes (10's of thousands of switch ports) and link speeds (10, 100, and 400 Gigabits). Using sFlow for packet capture doesn't replace traditional packet analysis, instead sFlow extends the capabilities of existing packet capture tools into the high speed switched network.

This article describes the sflow/tcpdump  and sflow/tshark Docker images, which provide a convenient way to analyze packets captured using sFlow.

Run the following command to analyze packets using tcpdump:
$ docker run -p 6343:6343/udp -p 8008:8008 sflow/tcpdump

19:06:42.000000 ARP, Reply 10.0.0.254 is-at c0:ea:e4:89:b0:98 (oui Unknown), length 64
19:06:42.000000 IP 10.0.0.236.548 > 10.0.0.70.61719: Flags [P.], seq 3380015689:3380015713, ack 515038158, win 41992, options [nop,nop,TS val 1720029042 ecr 904769627], length 24
19:06:42.000000  Continue reading

Microsoft Launches Azure Into Orbit With ExpressRoute

The cloud giant announced partnerships with SES, Viasat, and Intelsat to bring Azure to remote...

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Veteran AT&T Exec Gets Candid About Operator Challenges

Mobile network operators need to make money now and have “massive strengths” that remain...

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Google Fortifies Kubernetes Nodes Against Boot Attacks

The Google angle hardens the underlying Google Kubernetes Engine node against rootkits and...

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How to use Terminator on Linux to run multiple terminals in one window

If you’ve ever wished that you could line up multiple terminal windows and organize them in a single window frame, we may have some good news for you. The Linux Terminator can do this for you. No problemo!Splitting windows Terminator will initially open like a terminal window with a single window. Once you mouse click within that window, however, it will bring up an options menu that gives you the flexibility to make changes. You can choose “split horizontally” or “split vertically” to split the window you are currently position in into two smaller windows. In fact, with these menu choices, complete with tiny illustrations of the resultant split (resembling = and ||), you can split windows repeatedly if you like. Of course, if you split the overall window into more than six or nine sections, you might just find that they're too small to be used effectively.To read this article in full, please click here

Network Break 251: AWS Outage Is A Backup Reminder; What’s New At FutureNET?

Today's Network Break podcast delves into an AWS outage, tracks a slump in server sales, examines acquisitions by Commvault and Microsoft, and shares highlights from VMworld's FutureNET program. Guest Ed Horley stops by to share commentary and insights.

The post Network Break 251: AWS Outage Is A Backup Reminder; What’s New At FutureNET? appeared first on Packet Pushers.

BrandPost: Moving to SD-WAN? Consider Security Carefully, Say Experts and IT Managers

For those of you migrating from MPLS to SD-WAN, here’s a truism that all too often is forgotten: don’t overlook your security architecture.Failure to consider security as part of SD-WAN deployments is a major cause of security breaches.  Last year, enterprises with completed SD-WAN implementations were 1.3 times more likely to experience a branch office security breach than those without one, says Shamus McGillicuddy, Research Director at analyst firm Enterprise Management Associates.To read this article in full, please click here

The Week in Internet News: Covert Social Media Campaign Champions Military Rulers

The Internet as warfighting tool: Military rulers in Sudan and other countries are paying “Internet warfare” firms to develop social media campaigns to praise their leadership, the New York Times reports. The story highlights a social media company called New Waves, run by a former member of the Egyptian military and a self-described “researcher on Internet wars.”

Internet warfare, part 2: Meanwhile, a “virtual army” from mainland China has focused on recent protests in Hong Kong, with social media posts boosting government interests, the South China Morning Post writes. New recruits to the nationalist Diba group are taught how to use VPNs and circumvent the government firewall to reach the “battlefield” – social media pages and websites normally banned.

Protestors strike back: The Hong Kong protestors had their own Internet-related tactics, QZ.com reports. In response to threats of Internet shutdown, protestors began to use Bluetooth-based mesh networking technologies, allowing them to communicate through a network of devices that are linked locally, rather than over an Internet connection.

Encryption loves blockchain: The Tide Foundation, a nonprofit building an open-source framework for protecting data, has developed a blockchain-based encryption approach, Silicon Angle says.  This type of encryption is much more difficult Continue reading

Consuming Pre-Existing AWS Infrastructure with Cluster API

All the posts I’ve published so far about Kubernetes Cluster API (CAPI) assume that the underlying infrastructure needs to be created. This is fine, because generally speaking that’s part of the value of CAPI—it will create new cloud infrastructure for every Kubernetes cluster it instantiates. In the case of AWS, this includes VPCs, subnets, route tables, Internet gateways, NAT gateways, Elastic IPs, security groups, load balancers, and (of course) EC2 instances. But what if you didn’t want CAPA to create AWS infrastructure? In this post, I’ll show you how to consume pre-existing AWS infrastructure with Cluster API for AWS (CAPA).

Why would one not want CAPA to create the necessary AWS infrastructure? There are a variety of reasons, but the one that jumps to my mind immediately is that an organization may have established/proven expertise and a process around the use of infrastructure-as-code (IaC) tooling like Terraform, CloudFormation, or Pulumi. In cases like this, such organizations would very likely prefer to continue to use the tooling they already know and with which they are already familiar, instead of relying on CAPA. Further, the use of third-party IaC tooling may allow for greater customization of the infrastructure than CAPA Continue reading

Samsung Taps Amdocs to Combine 5G and Virtualization in ONAP

The companies are collaborating to support operators as they combine VNFs, SDN, and 5G in ONAP.

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Replacing a Network Element Config System with Git

In this post I’ll explore replacing the heart of a network operating system’s configuration mechanism with the software developers take on version control. It can be argued that network operating systems, or at least good ones, already have a version control system. It’s that very system that allows you to roll back and carry out operations like commit-confirmed. More specifically, this is a version control system like Git but not specifically git.

As my day job rotates around Junos, I’ll concentrate on that. So why would anyone want to rip out the heart of Junos and replace it with a git backed directory full of configuration snippets? Software developers and now automation skilled engineers want the advantages of being able to treat the network like any other service delivering node. Imagine committing human readable configuration snippets to a network configuration directory and having the network check it out and do something with it.

Junos already has a configuration engine capable of rollbacks and provides sanity through semantic and syntax commit time checks. Mgd (the service you interact with) provides mechanisms to render interfaces through YANG models and generates the very configuration tree you interact with. You could say mgd takes Continue reading

Experiences with approximating queries in Microsoft’s production big-data clusters

Experiences with approximating queries in Microsoft’s production big-data clusters Kandula et al., VLDB’19

I’ve been excited about the potential for approximate query processing in analytic clusters for some time, and this paper describes its use at scale in production. Microsoft’s big data clusters have 10s of thousands of machines, and are used by thousands of users to run some pretty complex queries. These clusters are in high demand and approximate query processing both saves their users time and lightens the overall load on the cluster.

What’s especially nice about this paper is that we get a glimpse into the practical adoption issues of persuading users that it’s ok to approximate too.

We have implemented support for query time sampling in production big-data clusters at Microsoft: these clusters consist of tens of thousands of multi-core, multi-disk servers and are used by developers from many different businesses including Bing, Azure, and Windows. In total, the clusters store a few exabytes of data and are primarily responsible for all of the batch analytics at Microsoft.

Approximate query support

Control over approximation is put into the hands of the user via extensions to the query language. In particular, support for expressing sampling requirements Continue reading

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