Sunday, 10 December 2017

IoT Security: Denial of Service Attack

In this post, I  demonstrate  a Denial of Service Attack that can be targeted towards any WiFi IoT device. In this case, I use a WiFi camera (TPLink's NC200 Camera) and show how easy it is to bring-it down and stop video streaming.  Not just the WiFi Camera, using this attack, one can bring-down any WiFi IoT device like Baby Monitor, Sprinkler, Motions Detectors, Fire Alarms etc. 

There can be many Denial of Service Attacks on WiFi protocol.  For this demo, I show De-authentication attack on a WiFi Camera. These attacks are very easy to generate and hence easy to bring-down the network. You don't need to know the Key / Password of the targeted WiFi Router.  

Most of the IoT devices come with a provision to monitor them remotely on your mobile using an app. With this kind of attacks, forget about receiving the IoT  alerts remotely  on your mobile app, you will not get alerts even if you are connected directly to the targeted WiFi Network.

Note: It is illegal to attack WiFi Networks. This post is for demonstration purpose and to make people aware of the attacks. 


The setup is as follows. 
  • A WiFi Router running OpenWRT's firmware.
  • TPLink's NC200 WiFi Camera is connected to the Router and streaming works perfectly fine.
  • Another OpenWRT Router to generate the Denial of Service Attacks. You need to install mdk3 onto this Router.   Lets call this Attacker Router. In fact, you can use any Linux Laptop too for this. It does n't need to be a Router. Usage of OpenWRT Router is my personal choice.

Attack Generation

The attack generation is very simple, as explained below.
  • As a first step,  you need to identify  the targeted AP's / Router's MAC Address. 
  • Goto Attacker Router's command prompt and  and copy the Router's MAC  into a temporary file ie echo E4:95:6E:42:00:0A > /tmp/black.txt
  • Create monitor interface and  issue the commands as shown below.

iw phy phy0 interface add mon0 type monitor
ifconfig mon0 up
mdk3 mon0 d -b /tmp/black.txt  -c 6

Thats it..  The above command de-authenticates all the connected clients from the targeted Router. The attack happens in such a way that the clients will not get any breathing space to do any meaningful data transmissions or receptions. 


We use TP-Link's NC200 camera for this. Demo Video is shown below. I have captured a rotating ceiling FAN to show a meaningful demo. Before the attack is generated,  you can see that FAN rotation is captured nicely. The moment the attack is generated (mdk3 command is given), streaming stops and you can see this as if the FAN is switched-off.

IoT Security: A Myth from Venkat on Vimeo.

It is as simple as that to bring down any IOT device or in fact the complete Network. Can't image the consequences though. Do we have products / solutions to detect or prevent this in IoT space? I know there are some enterprise grade solutions from companies like Mojo to detect (or mitigate some) some of these attacks. 

Wednesday, 1 November 2017

Case Study: WiFi Surveillance Cameras on Wireless Mesh

I have been waiting for a FREE weekend for a long time to install Surveillance Cameras in our  Apartment complex.After many "working' weekends, I have got FREE weekend in last week. Having known the differences between Analog and IP Cameras, I definitely want to install IP Cameras. But it involves a lot of wiring and again as a WiFi guy, I explored  WiFi Cameras. We did a site-survey and finally concluded that we need 8 cameras.

Personally I love to install  networking devices at customer's places. Fortunately I have got multiple chances right from college days where I tested my master's thesis on a live long-distance WiFi Link testbed in Kanpur and also got an opportunity to do a site-survey and install a relatively big Outdoor-WiFi testbed in Detroit, USA.  Now its time to install Wireless Cameras.


On some research on Internet, we have got this wonderful Wireless Surveillance  System from Zmodo.  It is a set of 8 WiFi cameras (4 Indoor and 4 Outdoor)  and NVR (which includes hard-disk too). It is available on Amazon. . One of my friends, Kiran Reddy shipped this product to me from USA.

Range Issues and Mesh Network 

Given the area of the premises, I know, one Router cannot cover the entire premises.  But again, I don't want to use any Cables. So, an alternative is to use a Mesh Network as backhaul to which all the WiFi cameras will connect to. Fortunately it is not an issue for me. I have developed multiple mesh solutions in the past and BANA is the most economical solution. So, BANA is a trivial choice.  Please check:

 Here is the cute little Router sleeping like lizard on the ceiling.


We have already decided on placement of Cameras. We have to decide on the placement of Routers. I thought to use 3 Routers to cover the entire premises. But after a little effort on Site-Survey, I find that two Routers could cover the entire premises. One Root device and one Repeater are sufficient. We have connected the NVR to the Root. The distance between Root and Repeater is around 25 meters with a big cement wall 

Powering the Cameras and Routers

You can't avoid one thing, whether your surveillance system is wired or wireless. That is Power supply. So we have added some plug points and it needs some wiring. But it is very little and not a big issue. 

So, now we have the power supply, Cameras  and Routers. All set. I have configured the Routers and Cameras before installing them. 

All the cameras are live in the first attempt itself. Four cameras have connected to Root and the other four connected with the Repeater.

 I have waited for 4 days to see if things are stable. The system seems to be running smoothly and quality is good. I will try to post some snapshots in some other post.


As per Zmodo, each camera needs a bandwidth of 1Mbps. So for 8 cameras we need 8Mbps of effective throughput in the Mesh network. 8Mbps of throughput in a mesh network is not a big deal for this mesh network.This Mesh network easily pulls-off this and quality is really good.  I will try to post the videos very soon.

Hardware and Softwae

The mesh network in this case is running on very ordinary Routers with a single 2.4Ghz Radio configured in 20Mhz (Do we really get 40Mhz channels in 2.4Ghz). It has 64MB of RAM and runs on MediaTek's processor MT7620N. Firmware is based on heavily modified OpenWRT and uses a proprietary Mesh Network protocol.


Point#1, To deploy  WiFi cameras on large scale, one needs to do an RF-survey. Point#2, you don't need a high-end expensive mesh products even for bandwidth sensitive applications like video streaming.

Friday, 3 March 2017

WiFi Router vs WiFi Range Extender vs WiFi System

WiFi Access is one thing that people can't live without. Traditionally you need something called WiFi Router through which you can access Internet.

WiFi Routers have a range of around 30 meters. In case you need to access beyond this range, you need something called WiFi Repeater / WiFi Range Extender. 

WiFi Repeaters have some limitations though.  Some of them are enumerated below.

  • WiFi Repeaters are not that easy to configure
  • Sometimes they create a new Network
  • There might be some compatibility issues between multiple vendors

WiFi Systems address the above limitations. They are easy to configure. There will be exactly one WiFi network with a typical WiFi System and there will be smooth roaming for clients between Routers.

People started moving towards WiFi Systems from traditional WiFi Routers / WiFi Repeaters and next few years belong to WiFi Systems. 

Thursday, 2 February 2017

Data Usage History with BANA

Reaching FUP limit is a nightmare :). But you can plan and use your bandwidth effectively if you know the  amount of data  that you (and other devices in your Network) consume every day / week / month.  Using BANA's UI you can know how much data is consumed everyday / week / month. You also can know which device eats up  data. 

Copying a screenshot of the data usage. 

Check our website, or read more posts on this blog to explore more features. Or shoot an email to us,

Connected Clients and their Bandwidth on BANA Router

Using BANA's Android app, you can see the list of Connected Clients in your Network. You can see the list from anywhere. Say if you are in office and want to see who all are connected to your home Network...

Copying a screenshot below

Port Scanning with BANA

Open Ports   make the clients  (Laptop, Mobile etc) devices vulnerable to cyber attacks. It would be good to know the opened ports and take appropriate action like killing an application or removing an app etc. 

BANA helps you to find the open ports on your Laptops, Tablets and Mobile Phones using an easy to use interface. Copying the screenshot below. . There are a maximum of 65536 ports that a system can have. You can choose the number of ports to scan using BANA's UI.

Tuesday, 31 January 2017

Parental Control With BANA WiFi Router / WiFi System

Everyone wants  control over their Internet connection, either it is permanently blocking a client (Laptops, Mobiles, Tablets etc) from accessing Internet or limiting access to kids. Especially with WiFi Routers we always should be very careful on who gets access to the Internet from your Network.  For eg. You have found an unwanted client device in your Network and you want to block access to it completely. Or Everday from 6PM to 7PM you want your kids to complete their homework and hence might want to block Internet Access during that period for selective clients or block Internet Access at dinner time. 

Unfortunately most of the WiFi Routers does n't let you to control the access. There are few WiFi Routers that let you to control the access. But they are very expensive. A WiFi system similar to BANA is priced around $400. You will get a BANA WiFi Rotuer for $40 and 3-BANA Router pack for $105. 

With BANA,  you will have full control over your network, including the following. 

  • Block / Unblock Internet Access for a selected client device
  • Schedule Internet Access for your kids (Say 6PM to 7PM on weekdays and 8PM to 9PM on weekends)
  • Block / Unblock Internet  Access for everyone (Say at dinner time)

You can control the above using a simple to use Web UI or through our Android App. You can also control the bandwidth consumption for each client in your Network. I will write about this in another post.  I am copying below the configuration screenshots from my BANA Routers.  You can see that with a single click you can block access to a client device.

We will start selling the Routers very soon. Share you email id  here,  to get your BANA. 

Sunday, 29 January 2017

Complete WiFi Picture with BANA

So, one can remotely monitor premises using BANA Routers and simple Webcams. BANA can also be used to add WiFi capabilities to Printers. What about core WiFi features? BANA supports almost every feature that you expect from your WiFi Router including Bandwidth Report (and Control), Data Usage Report,Parental Control and Port Scanning. Along with this BANA supports some other features that you might not have seen on other WiFi Routers or Systems. I will write more about each feature in coming days.  This post focuses on complete picture of your WiFi Network.

As I wrote in one of my earlier posts, a WiFi System is a combination of multiple co-operating WiFi Routers to cover larger areas that generally a single WiFi Router cannot do. Your clients (Laptops, Mobile Phones, Tablets etc) can connect to any of these Routers. You might want to know how the BANA devices are connected with each other. You would be curious to know how all your client devices are connected? We call this as Complete WiFi Picture. BANA UI presents this complete information in an easy to understand form. I have captured a screenshot of
my network (Copied below).

The Blue nodes are BANA devices and the green nodes are Client devices. 

Off-topic, our website is up, We will start selling the Routers very soon. Share you email id  here,  to get your BANA. 

Thursday, 26 January 2017

USB Printer becomes WiFi Printer with BANA

This is going to be very short and quick post. Check my previous posts before reading this, here, here and here :). 

Attach your USB printer to any of your BANA Routers to make your USB printer as a WiFi printer. Now you can  print documents from every client (Mobile phone, Tablet or Laptop) in your home. You don't need any PC for this and as usual absolutely no wiring is needed.  To print from mobile phones, you need to install apps like PrintBot. 

To summarize my posts on BANA's USB applications, you can attach the following USB devices to the BANA WiFi System.

  • USB Webcams to monitor your premises from anywhere in the world
  • 4G USB Dongle for main or backup Internet Connection
  • USB tethered mobile phone for main or backup Internet Connection
  • USB printer
  • File Server with USB drive (pen drive.. no hard-disks for now)

BTW the list does n't end here. We are open to support more devices as and when we receive new requirements from customers.

We will start selling the Routers very soon. Share you email id  here,  to get your BANA. 

Monday, 23 January 2017

4G Backup with BANA

In my last post, I wrote about Live Video Streaming using Webcams with BANA WiFi System. In this post I will write about 4G backup for your Network.

Internet is something that we can't live without. Internet connectivity is the key for the IoT applications to function properly. 

All of us get to see the problem of "Internet goes down suddenly". You might be in the middle of some important office call or in a video call with dearest relatives  when the Internet goes down and it is really a tough time :).  Or one of the sensors in the home have some important update (say smoke detection) and  your broadband Internet connection is down. Can't imagine the consequences.. right? What if there is a secondary Internet connection which comes up when your broadband (wired) connection goes down. BANA supports this.

With BANA, you can backup your Internet connection. You can use either a 3G/4G-USB Dongle or an USB-tethered mobile phone to backup your Internet connection.When your wired broadband Internet   goes down or not available, BANA will switch to 4G Network  and your WiFi clients or IoT applications will be online within few seconds. When your wired broadband Internet connection is up again, BANA will switch back to your wired connection.  This way your home is always connected with Internet and connectivity is always maintained for your IoT applications. 

 Attach the USB dongle to the  main (Root) BANA WiFi Router as shown below and configure (very minimal) some ISP settings. 

We will start selling the Routers very soon. Share you email id  here,  to get your BANA. 

Friday, 20 January 2017

Live Video Streaming from multiple cameras with BANA

So, what is unique about BANA? Just an affordable mesh solution for Home WiFi? As I mentioned in my earlier post, BANA is something beyond WiFi System and a true platform for IoT applications. We aim to bridge gap between all the Networks in your home and make a single Network. In this post I show a demo of "Live Video Streaming from multiple cameras with BANA " .

BANA Routers come with an USB2.0 port. We support multiple applications which use the USB 2.0 effectively. Live Video Streaming is one such application. Attach a USB webcam to a BANA Router and that's it. You don't need to configure anything else. Monitor your premises live from anywhere in the world using our Android app.

So, effectively with a "Less than $10" USB webcam you can monitor your house. A demo of the app shown below. I used 3 cameras for this demo.

Does it look cool? :) Please share your suggestions. This app and BANA Routers will be available very soon.  

A Nest cam costs around $200. Say you install 3 cameras. The total cost would be $600. An USB cam costs less than $10. So,  3 webcams + 3-unit BANA WiFi system costs you $30 + $100 = $130. No annual subscription fee BTW :). Moreover the cams are easy to install. Absolutely no wiring is needed. 

This is how I installed the BANA Router and attached the camera on a side wall. The Routers are very easy to mount. Each piece weighs just 39 grams with dimensions of 58*58*25mm  ie little less than your palm size. You can use any USB webcam of your choice. All the cameras we tested so far worked fine.  You can install upto 8 webcams. BTW,  BANA Routers are available in multiple colors including White, Blue, Black and Yellow. 

We will start selling the Routers very soon. Share you email id  here,  to get your BANA. 

Thursday, 19 January 2017

WiFi System : BANA

What is WiFi System?

A WiFi System is a collection of WiFi Routers  which talk and cooperate among themselves to form one single big WiFi Network. For users it looks as if there is a single WiFi Router with wider range of coverage. To say in little technical words, a WiFi System is nothing but a Wireless Mesh Network and form a single IP Subnet. 

Why do we need a WiFi System?

 The answers is simple, to increase the WiFi coverage in your premises. We have Range-Extenders to do this job? Yes..They are available for far lesser prices than the WiFi Systems . But a WiFi System is more than the Repeater or Range-Extender. 
  • With Range-Extender a separate WiFi network is created. For every change (For e.g change keys) you make at the Main Router, you will have to make those changes at Range-Extenders also. 
  • All information like clients statistics (if at all) is maintained separately for each Range Extender.
  • WiFi Systems can be managed using a centralized common interface typically through Mobile Apps or  browser. Using this centralized interface one can configure Network Names, Keys and features like Parental control. With single click the settings will be applied for all Routers in the Network. .
  • Some WiFi Systems provide seamless roaming across the Network. Meaning, your skype call does n't disconnect when you move from one corner of house to another.
  • Range-Extenders are not that easy to configure, whereas with WiFi System , the configuration is very simple and network can be scaled-up very easily.

Typically a Router can cover around 1000 square feet (Use Google to convert into other units :)) . More the number of Routers, better the coverage. There are some limitations for this. I will try to write more on this in a separate post.


A typical WiFi System consist of 2 or 3 Routers.  The price varies from $300 to $450 based on the number of Routers  and vendor. Too much... is n't it? :)

A typical range extender costs around  $30. So a combination of a reasonably good WiFi Router + 2 Range extenders will not cost more than $100. 


WiFi Systems typically have 2 radios with  one operating  in 2.4Ghz (11N) band and the other in 5Ghz band (11AC).  You may see an effective throughput of 60Mbps to 400+Mbps.  Please see this page for throughput numbers and comparison.

Throughput of upto 60Mbps to 90Mbps is achievable with a single 11N radio also. Also not every application needs 100+Mbps throughput.

However please note that the effective throughput is limited by your ISP speeds. So the effective throughput that you get is the minimum of your Internet Speed and throughput of WiFi System. With a 40Mbps connection you can have 16 simultaneous HD videos streams (from Youtube) and more than 30 simultaneous normal video streams (from Youtube).

So for typical usage, 60Mbps to 90Mbps of throughput provide an excellent Quality of Service.

Future WiFi  System

From the above discussion, we can see that  WiFi Systems have the advantage of easy to setup and use. However the price is too high when compared to the value addition that they bring.

On the other hand, a Range-Extender is not that easy to setup and lacks features like Parental control, bandwidth monitoring etc. However the price is very low when compared with that of WiFi Systems.

So the ideal combination is a WiFi System at the price of Range-Extenders.  Nearhop has addressed this and developed an alternate WiFi System, "Bana - a WiFi System and a perfect platform for IoT".   It is not just a WiFi System, but something  beyond that with never seen features. I will blog more about these exciting features in the coming days. The product will be available in the market very soon. We are trying to bring down the price below $100 for a 3-unit WiFi System.We will start selling the Routers very soon. Share you email id  here,  to get your BANA.