Workaround for virtualenvwrapper for windows postactivate script

Virtualenvwrapper’s windows port (virtualenvwrapper-win) helps to manage your venvs on windows platform, yet it is not so straigtforward about using hooks like postactivate. That is what official documentation has to say about this: Hooks To run some commands after mkvirtualenv you can use hooks. First you need to define VIRTUALENVWRAPPER_HOOK_DIR variable. If it is set mkvirtualenv

Ansible up and running

After much delay – I’ve finally found time to take a look at Ansible.  I’ve spent some time looking at possible platforms to automate network deployment and Ansible seems to be a favorite in this arena.  One of the primary reasons for this is that Ansible is ‘clientless’ (I’m putting that in quotes for a reason, more on that in a later post).  So unlike Chef, Puppet, and Salt (Yes – there are proxy modes available in some products) Ansible does not require an installed client on the remote endpoints.  So let’s get right into a basic lab setup.

While the end goal will be to use Ansible to automate network appliances, we’re going to start with the a more standard use case – Linux servers.  The base lab we will start with is two servers, one acting as the Ansible server and the second being a Ansible client or remote server.  Both hosts are CentOS 7 based Linux hosts.  So our base lab looks like this…

image
Pretty exciting right?  I know, it’s not, but I want to start with the basics and build from there…

Note: I’ll refer to ansibleserver as Continue reading

Fscking Visual Studio Code JS Hello World

The reason Linux never succeeded on the desktop is the lack of usability testing. Open-source programmers hate users, and created such an ugly baby that only a fanboy could love it. It's funny watching the same thing happen to "Visual Studio Code", Microsoft's answer to the Atom editor. You'd think with Microsoft behind it, that it'd be guided by usability testing. The opposite is true. It spends a lot of time hyping it, but every time I try to use it, I encounter unreasonable hurdles for the simplest of things. It's the standard open-source paradigm -- they only spend effort to make something work in theory without the extra effort to make it usable in practice.

The most common thing you'll want to do is first create a "hello world" program, then debug it. As far as I can tell, there are no resources that'll explain how to do this. So, for JavaScript on Windows, I thought I'd explain how this works.

Firstly, you'll need to install NodeJS and VS Code. Just choose the defaults, it's uneventful.

Secondly, you need to understand how projects work. This is the first hurdle everyone has with an IDE. You don't simply run the Continue reading

Will Public Cloud Make Us Prisoners Of Pricing?

Let's say the vast majority of compute workloads in the world migrates to public cloud. Will public cloud pricing then become extortionate? Seems plausible if you assume that the technical talent migrates to public cloud companies. In that scenario, public cloud consumers are beholden to their technical master and would have to pay whatever is asked so that they can get their business done. However, I think the situation is more complex than that...

Securing BGP: A Case Study (3)

To recap (or rather, as they used to say in old television shows, “last time on ‘net Work…”), this series is looking at BGP security as an exercise (or case study) in understanding how to approach engineering problems. We started this series by asking three questions, the third of which was:

What is it we can actually prove in a packet switched network?

From there, in part 2 of this series, we looked at this question more deeply, asking three “sub questions” that are designed to help us tease out the answer this third question. Asking the right questions is a subtle, but crucial, part of learning how to deal with engineering problems of all sorts. Those questions can be summed up as:

  • Is the path through this peer going to pass through someone I don’t want it to pass through?
  • Is the path this peer is advertising a valid route to the destination?

Let’s quickly look at the first of these two to see why it’s not provable in the context of a packet switched network, using the network diagram below.

bgp-sec-02

When working with BGP at Internet scale, we tend to think of an autonomous system as one “thing”—we Continue reading

VoIP phone with default password can be used for covert surveillance

If you’d like an attacker to eavesdrop on your calls made on VoIP phones, then leave the default password in place. If not, then change it.Using default or weak passwords will continue to bite companies, but this time instead of spying via IP cameras, it was enterprise-grade VoIP phones being pwned. When a client asked information security consultant Paul Moore how to improve security without disrupting ease of VoIP phone deployment, Moore discovered the company was using the default password.To read this article in full or to leave a comment, please click here

Egnyte Architecture: Lessons Learned in Building and Scaling a Multi Petabyte Distributed System

This is a guest post by Kalpesh Patel, an Architect, who works from home. He and his colleagues spends their productive hours scaling one of the largest distributed file-system out there. He works at Egnyte, an Enterprise File Synchronization Sharing and Analytics startup and you can reach him at @kpatelwork.

Your Laptop has a filesystem used by hundreds of processes, it is limited by the disk space, it can’t expand storage elastically, it chokes if you run few I/O intensive processes or try sharing it with 100 other users. Now take this problem and magnify it to a file-system used by millions of paid users spread across world and you get a roller coaster ride scaling the system to meet monthly growth needs and meeting SLA requirements.

Egnyte is an Enterprise File Synchronization and Sharing startup founded in 2007, when Google drive wasn't born and AWS S3 was cost prohibitive. Our only option was to roll our sleeves and build an object store ourselves, overtime costs for S3 and GCS became reasonable and because our storage layer was based on a plugin architecture, we can now plug-in any storage backend that is cheaper. We have re-architected many of Continue reading

Worth Reading: Virtualization Slides

Server virtualization is a relatively heavy way to drive up utilization on servers, and it has been particularly well suited for Windows workloads where various container technologies have not yet been brought to bear. … While enterprises are not apt to change platforms quickly, the slowing growth in server virtualization means they have virtualized the stacks they can and that they are probably looking at how they might deploy containers either on top of or instead of virtual machines. -via the next platform

The post Worth Reading: Virtualization Slides appeared first on 'net work.

New to Openstack and worried about networking pre-setup? Try VXLAN or GRE first!


As an avid developer/coder I tend to try out various languages. I do have my favorites but when I embark on a new tool or language the first experience definitely leaves behind a mark. Failing at  getting something to work in the very first try is fine as long as you don't end up hating the technology. I guess I've iterated this over and over again on other posts but networking is complex and hard. Getting it right does require some (not really, it's actually a lot :-) ) amount of experimentation. With technologies changing every so often it's imperative to at least give them a try if not jump the train and adopt them.

Openstack being an opensource project as massive as the linux kernel it does have a ton of features. The neutron component that facilitates networking is quite a handful for beginners and it gets even messier when you will need to configure neutron to work with the network architecture that is already present in your datacenter. Getting a production ready neutron setup with say VLAN backed networks is a handful. After working with Neutron for some time now, i've realized that it isn't as bad Continue reading

CCDE – DMVPN Crypto Design Considerations

This post will describe some of the crypto design considerations for DMVPN.

DMVPN Overview and Crypto Overhead

First let’s have a quick recap of what Dynamic Multipoint VPN (DMVPN) is. DMVPN is an overlay technology where multi point GRE tunnels are used to form an overlay where a routing protocol will run across the overlay. DMVPN is a hub and spoke technology where the DMVPN hub acts as a centralized control plane. DMVPN uses Next Hop Resolution Protocol (NHRP) to register the IP addresses of the spokes with the hub. When a router looks in its routing table, the next-hop will be the IP address of the tunnel, not the real outside IP which must be used for the GRE encapsulation. To find the outside IP of the spoke, NHRP is used to resolve the next-hop to the real outside IP.

DMVPN runs over public transport. This means that it’s possible to snoop the traffic while in transit. To prevent this from happening, DMVPN is often combined with IPSec to encrypt the packets. IPSec can run in two modes, transport mode and tunnel mode. In transport mode, the original IP header is not encrypted and there is no additional IP Continue reading

Meet the Engineering Team at Citrix NetScaler

@mrtugs Tweet on Citrix

We had some great vendor presentations at Networking Field Day 11 and in the face of some pretty stiff competition, Citrix won my inaugural Best surprise award, which I have just invented.

Citrix NetScaler

It’s not that the Citrix NetScaler Application Delivery Controller (ADC) is a particularly unique product; after all, I could as easily implement load balancing with the open source HAProxy, and there are impressive ADC hardware vendors in the commercial space, including the ubiquitously expensive F5 Networks and disruptive challenger A10 Networks. What grabbed my interest me however were the performance statistics of the NetScaler appliances, and specifically the process through which the performance was achieved by the Citrix engineering team.

Intel DPDK

If I might side track for a moment, at Networking Field Day 10, Intel discussed their DPDK (Data Plane Development Kit) designed to optimize soft-switched packet performance on their CPUs. Intel had noted that the performance of Open vSwitch (OVS) was nowhere near the native ability of the CPU, and consequently they invested time analyzing in scary detail exactly how packets flowed in order to find out where the bottlenecks were, and to see whether those could be eliminated or optimized in Continue reading

IDG Contributor Network: Why companies are becoming more likely to pay when struck by ransomware

A quarter of companies have made their mind up when it comes to a ransomware attack. They're paying the ransom, according to a new study.Twenty-four percent of companies say they would pay. And not only would they cough-up the money, but 14% of the polled would pay $1 million or more to prevent the attack, according to findings by the Cloud Security Alliance (CSA) and Skyhigh, who have compiled the study. The CSA is a non-profit promoting best-practices in cloud use; Skyhigh is a cloud security company.The CSA surveyed 200 IT and security professionals across sectors worldwide. The researchers have been examining cloud take-up along with risk. They think that cyberattacks overall are a concern for enterprises "when it comes to moving their systems of record to the cloud," CSA and Skyhigh say in their report.To read this article in full or to leave a comment, please click here

Russian cyberspy group uses simple yet effective Linux Trojan

A cyberespionage group of Russian origin known as Pawn Storm is infecting Linux systems with a simple but effective Trojan program that doesn't require highly privileged access.Pawn Storm, also known as APT28, Sofacy or Sednit, is a group of attackers that has been active since at least 2007. Over the years, the group has targeted governmental, security and military organizations from NATO member countries, as well as defense contractors and media organizations, Ukrainian political activists and Kremlin critics.The group is known for using zero-day exploits -- exploits for previously unknown vulnerabilities -- as well as other infection techniques like spear-phishing emails with malicious attachments. Its primary tool is a Windows backdoor program called Sednit, but the group also uses malware programs for Mac OS X, Linux and even mobile operating systems.To read this article in full or to leave a comment, please click here

New products of the week 2.15.2016

New products of the weekOur roundup of intriguing new products. Read how to submit an entry to Network World's products of the week slideshow.VMware Workspace ONEKey features: Workspace ONE delivers a digital workspace that integrates device management, application delivery and identity management technologies to offer combined benefits on a single secure mobile platform to enable management and delivery of business critical resources.To read this article in full or to leave a comment, please click here

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