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Category Archives for "Networking"

Musing on Nerd Knobs

Henk left a wonderful comment on my SDN will not solve real-life enterprise problems blog post. He started with a bit of sarcasm:

SDN will give more control and flexibility over the network to the customer/user/network-admin. They will be able to program their equipment themselves, they will be able to tweak routing algorithms in the central controller. They get APIs to hook into the heart of the intelligence. They get more config-knobs. It's gonna be awesome.

However, he thinks (and I agree) that this vision doesn’t make sense:

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Creating Templates for TextFSM and ntc_show_command

Less than two weeks ago I wrote a post about an Ansible module called ntc_show_command. For those that didn’t read that post, you should, but ntc_show_command is a multi-vendor module that can automate converting raw text from show commands into structured data, namely JSON.

We’ve already had several pull requests enhancing the architecture, so the community support is off to a great start! But in order to really make an impact, we (me, you, and fellow network engineers) need to continue to contribute templates to the project repository. Templates are key to converting the raw text into JSON.

This post will walk through how to create a template for two different commands. We’ll take a look at show version for Cisco NX-OS and display version for HP Comware 7.

The first thing that we’ll need to do is get the raw text output that we want to JSONify. We’ll start with show version.

Below is the sample output that we’ll work with and this file will be saved as tests/cisco_nxos/cisco_nxos_show_version.raw within our project directory.

Cisco Nexus Operating System (NX-OS) Software
TAC support: http://www.cisco.com/tac
Copyright (C) 2002-2014, Cisco and/or its affiliates.
All rights reserved.
The copyrights to certain  Continue reading

Codec Negotiations in Your CCIE Collaboration Preparation

Codec negotiation is a topic that gets glossed over without much consideration in the studies of most students. There’s really not much to it, right? All we have to do is slap a couple of Regions on two different system endpoints and…voila, we have successfully negotiated a codec! Can it be that simple? Like most answers to rhetorical questions in the tech world, “It depends.” A simplistic approach like the one just described above is a great place to start, but it doesn’t take into account key call flow elements such as early/delayed offer, Audio Codec Preference Lists, or call routing across CUBE, CUCM or CUCME. What if the codec should be different based on the originator of the call? These are all examples of key issues involving codec negotiation that we must wrap our mind around if we are to be successful in our CCIE Collaboration endeavors.

Let’s examine the requirement of routing a call between a 9971 Phone registered to the HQ CUCM cluster (HQ Phone 1) and a 7965 Phone registered to the SB CUCM cluster (SB Phone 1). In this example, consider that a SIP Trunk is configured directly between clusters in order to route Continue reading

Linux Core 6.3 as Routing and Switching VMware Appliance

Two weeks ago I finished creating a network host based on Linux Core 6.3 installed on WMware x86-64 virtual machine. I loaded Core Linux with several network extensions that allows host to generate, measure, route network traffic and scan networks. I also wrote a short article that contains a list of loaded extension.

Then I went further with the ​project and my goal was to build L3 switch and router based on  Core Linux 6.3 loaded with Open vSwitch, Quagga, Bird and Keepalived extension. Those are the right extensions that turned the network host  to routing and switching appliance. Furthermore the routing daemons Quagga and Bird and multilayer switch Open vSwitch are used in many large production networks.

The R&S appliance I built can be used for learning networking on Linux, routing and switching. It is available for download in Download section. For those who are interested in installation steps the whole process of extension installation  is described in this article.

The virtual VMware appliance is based on Linux Core network host image and it contains all the extensions listed here plus the following extensions:

openvswitch - 2.4.90
quagga - 0.99.24.1
bird - 1.5.0
keepalived - 1.2.19

Note Continue reading

Smart refrigerator hack exposes Gmail login credentials

A team of hackers recently discovered a man-in-the-middle vulnerability in a Samsung smart refrigerator that can be exploited to steal Gmail users' login credentials, The Register reported this week.Hackers from security company Pen Test Partners discovered the flaw while participating in an Internet of Things (IoT) hacking challenge at the Def Con security conference earlier this month. The smart refrigerator, Samsung model RF28HMELBSR, is designed to integrate the user's Gmail Calendar with its display. Samsung implemented SSL to secure the Gmail integration, but the hackers found that the device does not validate SSL certificates, opening the opportunity for hackers to access the network and monitor activity for the user name and password used to link the refrigerator to Gmail.To read this article in full or to leave a comment, please click here

Worth Reading: Open Source (Part 1)

How is the Internet Engineering Task Force (IETF) broken? Can you count the ways? The process is too slow, the standards are often opaque, the results are often complex and difficult to deploy; any engineer who’s been in the networking field long enough most likely can recite a litany of complaints. via network computing


This is the first of a four part series on open source versus open standards.

The post Worth Reading: Open Source (Part 1) appeared first on 'net work.

STEM fields dominate ranking of college majors

Petroleum engineering majors earn the highest mid-career salaries, followed by nuclear engineering majors, according to a new ranking from PayScale.The research company, which specializes in compensation data, ranked 319 majors at the bachelor level based on how much money graduates in each field are making. The top 25 bachelor-level majors all have mid-career median pay numbers above $100,000, and the vast majority of them are STEM majors. RELATED STORIES: Not your father's computer science building Computer science surge sparks campus building boom Maker spaces boost student tech innovation Among many disciplines in the compsci arena, graduates who earn a bachelor’s degree in computer science and engineering were ranked highest (6th place), reporting a median mid-career salary of $115,000. Computer science majors (ranked 18th) earn a median mid-career salary of $105,000. (See also: Top 25 computer science colleges)To read this article in full or to leave a comment, please click here

Tor security concerns prompt largest dark market to suspend operations

Agora, the Tor network's largest black marketplace, has been temporarily shut down because its administrators worry the website is vulnerable to recent methods of exposing Tor Hidden Services.Hidden services are websites that can only be accessed from within the Tor network, which is specifically designed to hide the IP address of both servers and users. The built-in anonymity safeguards have made Tor Hidden Services the preferred method for running online marketplaces that allow buying and selling illegal goods like drugs, guns, stolen credit card details and more.The largest of these so-called dark markets was Silk Road, which was eventually shut down by the FBI in 2013. Many similar websites have appeared since then and some were targeted in subsequent international law enforcement raids, but Agora survived and surpassed even Silk Road in size and popularity.To read this article in full or to leave a comment, please click here

Worth Reading: Micromanaging Compute

In people management, it’s generally accepted that micromanaging a person is often a bad idea. Micromanagement removes the opportunity for the individual to find a better path than originally conceived. It also often focuses on the specific steps of a process, but unfortunately removes the context that would help someone understand how to improve the process. via infoworld

The post Worth Reading: Micromanaging Compute appeared first on 'net work.

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