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Category Archives for "Networking"

Project Jengo Strikes Its First Targets (and Looks for More)

Jango Fett by Brickset (Flickr)

When Blackbird Tech, a notorious patent troll, sued us earlier this year for patent infringement, we discovered quickly that the folks at Blackbird were engaged in what appeared to be the broad and unsubstantiated assertion of patents -- filing about 115 lawsuits in less than 3 years, and have not yet won a single one of those cases on the merits in court. Cloudflare felt an appropriate response would be to review all of Blackbird Tech’s patents, not just the one it asserted against Cloudflare, to determine if they are invalid or should be limited in scope. We enlisted your help in this endeavor by placing a $50,000 bounty on prior art that proves the Blackbird Tech patents are invalid or overbroad, an effort we dubbed Project Jengo.

Since its inception, Project Jengo has doubled in size and provided us with a good amount of high quality prior art submissions. We have received more than 230 submissions so far, and have only just begun to scratch the surface. We have already come across a number of standouts that appear to be strong contenders for invalidating many of the Blackbird Tech patents. This means it is Continue reading

53% off Cable Organizer Electronics Accessories Travel Bag – Deal Alert

Do you have a ball of tangled up wires and adapters somewhere in the bottom of your bag? This Universal Electronics Accessories Travel Organizer provides a flexible organization solution for your electronics and computer accessories. It helps make you better organized with all the small items and gadgets.  Made of durable and weather-resistant nylon with well padded semi-flexible covers.  It's compact size of  8.8“ x W 6.1"allows it to easily stored in you laptop bag or backpack.  This travel organizers typical list price of $18.99 has been reduced 53% to just $9. See this deal on Amazon.To read this article in full or to leave a comment, please click here

62% off RAVPower 14000mAh Portable Car Jump Starter – Deal Alert

A compact power bank, a car jump starter, and a LED flashlight, all fit into a minimal and portable design. Whether it is your car or your USB devices, never run out of power again. Store it in the glovebox or simply drop it in your bag. Have a concentrated 14000mAh source of power always with you -- enough for up to 20 vehicle jumpstarts or many device recharges before the unit itself needs to be recharged. RAVPower's jump starter typically lists for $160 but is currently discounted 62% on Amazon to just $64. See the discounted car jumper now on Amazon. To read this article in full or to leave a comment, please click here

Arista reaches for the hybrid clouds

Many years ago, when Arista Networks was in its infancy, its charismatic and sometimes controversial (at least to the folks at Cisco) CEO talked about how the company’s software-first approach would disrupt the networking industry. Just a few years later, the company stands a $1.7 billion revenue company with a dominant position in the webscale industry and a market cap of over $13 billion, so clearly CEO Jayshree Ullal’s prophecy came true.Arista’s software rigor enabled the company to quickly jump into verticals where low latency and high performance mattered. Also, because of Arista’s software prowess, the company has been able to expand its addressable market to see to the networking needs of dense virtualization and containerized environments, as well as private cloud deployments, and quickly adapt the latest and greatest silicon.To read this article in full or to leave a comment, please click here

Arista reaches for the hybrid clouds

Many years ago, when Arista Networks was in its infancy, its charismatic and sometimes controversial (at least to the folks at Cisco) CEO talked about how the company’s software-first approach would disrupt the networking industry. Just a few years later, the company stands a $1.7 billion revenue company with a dominant position in the webscale industry and a market cap of over $13 billion, so clearly CEO Jayshree Ullal’s prophecy came true.Arista’s software rigor enabled the company to quickly jump into verticals where low latency and high performance mattered. Also, because of Arista’s software prowess, the company has been able to expand its addressable market to see to the networking needs of dense virtualization and containerized environments, as well as private cloud deployments, and quickly adapt the latest and greatest silicon.To read this article in full or to leave a comment, please click here

Arista reaches for the hybrid clouds

Many years ago, when Arista Networks was in its infancy, its charismatic and sometimes controversial (at least to the folks at Cisco) CEO talked about how the company’s software-first approach would disrupt the networking industry. Just a few years later, the company stands a $1.7 billion revenue company with a dominant position in the webscale industry and a market cap of over $13 billion, so clearly CEO Jayshree Ullal’s prophecy came true.Arista’s software rigor enabled the company to quickly jump into verticals where low latency and high performance mattered. Also, because of Arista’s software prowess, the company has been able to expand its addressable market to see to the networking needs of dense virtualization and containerized environments, as well as private cloud deployments, and quickly adapt the latest and greatest silicon.To read this article in full or to leave a comment, please click here

What is edge computing and how it’s changing the network

Edge computing allows data produced by internet of things (IoT) devices to be processed closer to where it is created instead of sending it across long routes to data centers or clouds.Doing this computing closer to the edge of the network lets organizations analyze important data in near real-time – a need of organizations across many industries, including manufacturing, health care, telecommunications and finance.“In most scenarios, the presumption that everything will be in the cloud with a strong and stable fat pipe between the cloud and the edge device – that’s just not realistic,” says Helder Antunes, senior director of corporate strategic innovation at Cisco.To read this article in full or to leave a comment, please click here

What is edge computing and how it’s changing the network

Edge computing allows data produced by internet of things (IoT) devices to be processed closer to where it is created instead of sending it across long routes to data centers or clouds.Doing this computing closer to the edge of the network lets organizations analyze important data in near real-time – a need of organizations across many industries, including manufacturing, health care, telecommunications and finance.“In most scenarios, the presumption that everything will be in the cloud with a strong and stable fat pipe between the cloud and the edge device – that’s just not realistic,” says Helder Antunes, senior director of corporate strategic innovation at Cisco.To read this article in full or to leave a comment, please click here

IDG Contributor Network: Is SD-WAN better than MPLS?

Lately, our clients with an MPLS WAN are starting to ask: “Should we get rid of our MPLS and go to SD-WAN? Is SD-WAN better?”I don’t mean to make this question sound childish (since it’s a fantastically good question), but it reminds me of a mistake I made when my 9-year-old son asked me a question the other day.He is obsessed with baseball, so, of course, he asked me something all of us baseball fans have wondered at some point: “Daddy, which is better… a guy who hits .250 with 50 home runs or a guy who hits .300 with 10 home runs?”To read this article in full or to leave a comment, please click here

IDG Contributor Network: Is SD-WAN better than MPLS?

Lately, our clients with an MPLS WAN are starting to ask: “Should we get rid of our MPLS and go to SD-WAN? Is SD-WAN better?”I don’t mean to make this question sound childish (since it’s a fantastically good question), but it reminds me of a mistake I made when my 9-year-old son asked me a question the other day.He is obsessed with baseball, so, of course, he asked me something all of us baseball fans have wondered at some point: “Daddy, which is better… a guy who hits .250 with 50 home runs or a guy who hits .300 with 10 home runs?”To read this article in full or to leave a comment, please click here

Interview Questions for CCNA Candidates with Answers- Basics II


After out Part-I, we are again with Part-II

CCNA Interview Questions

What command copies router configuration from NVRAM to a file server? 
copy startup-config tftp

What command assigns and enables IPX on an interface? 
ipx network 4a

How does TCP provide flow control and error checking? 
Acknowledgements and windowing.

Using Cisco IOS, what PPP data compression methods can be used?  
Stacker and Predictor.

What command can verify Application layer connectivity? 
Telnet.

What command switches from User to Privileged mode? 
enable

What command will deny all telnet traffic from subnet 2.1.3.0? 
deny all telnet traffic from 2.1.3.0

Which of the following exist at the Transport Layer?
LLC
IP
SQL
UDP*
ARP

What command line keyword matches Ethernet_SNAP? 
snap

Among the five classes of TCP/IP addresses, how many are available to the public? 
3.

After entering the command ‘router igrp 50,’ what command enables IGRP on the router for interace E1, with an address of 155.88.3.5 and a mask of 255.255.255.0? 
network 157.89.0.0

In what OSI layer do EBCDIC and ASCII exist? 
Presentation.

What command Continue reading

Are VXLAN-Based Large Layer-2 Domains Safer?

One of my readers was wondering about the stability and scalability of large layer-2 domains implemented with VXLAN. He wrote:

If common BUM traffic (e.g. ARP) is being handled/localized by the network (e.g. NSX or ACI), and if we are managing what traffic hosts can send with micro-segmentation style filtering blocking broadcast/multicast, are large layer-2 domains still a recipe for disaster?

There are three major (fundamental) problems with large L2 domains:

Read more ...

A short Story on vPC- Virtual Port Channel in Cisco Datacenter Environment

Today I am going to talk about vPC and vPC+. These two technologies are used in the datacenter environment over the Cisco Nexus Switches where you bundled the links.

vPC stands for Virtual Port Channel and is a virtualized technology, So it allows links that are physically connected to two different Cisco Nexus 7000 Series devices to appear as a single port channel to a third device. The third device can be a switch, server, or any other networking device that supports link aggregation technology. 

There are lot of benefits of vPC which can allow to work better in your datacenter environment


  • It actually eliminates Spanning Tree Protocol blocked ports
  • with the help of vPC, you can use all the uplink available bandwidths
  • Allows dual homed servers to operate in active-active mode
  • Providing Fast convergence on link failures
  • Providing dual active default gateways for servers
  • Simplify your network design and build high resilient and robust Layer 2 Network.
  • Excellent Scalability and seamless virtual machine mobility.
So now I will talk about the various components used in the vPC environment. I hope datacenter guys already heard and know about these components. I will just put the component and the meaning of Continue reading

Cisco Router as Terminal Server- Why and how to configure

Today I am going to talk about the Cisco Router as a Terminal server in the datacenter environment. So the question is why and where we are going to use the terminal server?

Let's talk about the Terminal server what exactly is and why we are using the Terminal server in the datacenter environment.

Terminal Server:
A terminal server commonly provides out-of-band access for multiple devices. A terminal server is a router with multiple, low speed, asynchronous ports that are connected to other serial devices, for example, modems or console ports on routers or switches.

Fig 1.1- Cisco Router as Terminal Server

A terminal server works via a reverse telnet operation. Next, connect the asynchronous octal cable(s) to the 2511's 68-pin SCSI interface(s). Then connect a rolled console cable from the COM1 port (serial) on your PC to the console port on the terminal server. Power the device on and use a terminal emulator such as HyperTerm to connect.

The terminal server allows you to use a single point to access the console ports of many devices. A terminal server eliminates the need to configure backup scenarios like modems on auxiliary ports for every device. You can also configure Continue reading

Flow Trend

The open source sflow-rt/flow-trend project displays a real-time trend chart of network traffic that updates every second. Defining Flows describes how to break out traffic by different traffic attributes, including: addresses, ports, VLANs, protocols, countries, DNS names, etc.
docker run -p 6343:6343/udp -p 8008:8008 sflow/flow-trend
The simplest way to run the software is using the docker. Configure network devices to send standard sFlow telemetry to Flow Trend. Access the web user interface on port 8008.