Running Etherape without root or sudo

To run Etherape without having to use sudo each time then, after installation, run the following command:

sudo setcap cap_net_raw,cap_net_admin+eip /usr/bin/etherape

Your executable may be in another location.

Make sure you understand the security implications of doing this.

You will need your administrator to run this command for you if you do not have sudo access.

New frontiers in communication systems

New research by the universities of Bristol, Keio and industrial partners have unlocked 80 THz of fibre-optic bandwidth that will enable future exascale data centres and transform 5G networks.

The research on optical communication technologies, wavelength division multiplexing and networks form the backbone of every wired network across the whole Internet. Work until now has been focused and limited on utilizing ~11 THz of bandwidth (C and L Band) centred at 193 THz.
Optical networks based on this frequency bands have been able to support up to 230 channels at 50 GHz spacing.

The technology fabricated and tested is based on cascaded arrayed waveguide gratings (AWGs) and is designed to potentially construct a 1600 x 1600 wavelength router that can guide data at the speed of light. Specially designed quantum dot chips are used for light sources.

This single passive optical system can route immense information offering manifold increase from current systems. It can single-handedly interconnect over one million end points while offering at least ten Gb/s per end point. Critically it is also future proof since it's transparent to any communication signal and it can also potentially consume zero power due to its passive nature.

Read the full article at New frontiers in communication systems.

Dropbear SSH server on Android

It's safe to say that if you're reading this then you know why one would want an SSH server running on your Android device. Personally I have SSH running on all my Linux boxes because it makes life so much easier, and I'm sure I do not need to explain why. Having an SSH server start on boot is simply a lot more convenient!

There are a number of apps on the Android market but most of them are utterly useless with one exception: SSHDroid.

If you are likely to use SSH once in a while then it may be easier for you to just install SSHDroid on your device and start it when needed, and I have been happy with it for a while.

However:

1. It's an ugly app that sits in your notification tray once it has been started and uses up RAM and CPU. I want a background app.
2. SSHDroid refuses to run if it cannot access adverts unless you pay for it. I block all adverts because they get on my nerves.
3. All it does is drop a copy of Dropbear anyway, so you may as well do that yourself.
4. Dropbear will happily run in the background and uses tiny amounts of CPU when active, so you can imagine how little it does when idle.
5. If you can compile Dropbear yourself you can choose the options that you want.

As I'm sure you are aware there is no package delivery system for this kind of application in Android, but Android runs on a modified Linux kernel - this makes things so much easier! The result being that the following process is ridiculously easy assuming that your OS has:

• su or sudo (root)
• init.d support (or another way to run scripts at startup)

The only problem, really, is that the filesystem and methods used in Android aren't exactly standard compared to other *nix systems, but its not massively different. The result being that there are a number of ways that you can get things to work, so I'll simply show you what I have done. If I was doing this to a number of devices or in a corporate environment then I would use a bit more planning.

Running DIMES Agent at start-up

The DIMES Agent does not run until logged in on Windows Vista and later due to UAC as the Windows service, although installed, is blocked automatically by the operating system.

There is still a way to make sure the Agent loads at system start, however: by running it as a scheduled task.

Note: The agent is unable to interact with the desktop so you will not be able to view statistics or change settings once running (but you can through the website). It will run in the background only. Also, on Windows 7 at least, you cannot stop the task once it is running unless you kill it.

Once installed, delete the shortcut from the Startup folder as it is no longer needed, and will probably cause problems later on.

Open the DIMES Agent with the Start Menu shortcut if it hasn't loaded already and input your user details.

Close the DIMES Agent.

Then, open Scheduled Tasks in the Control Panel.

Select Action and Create Task...



Once the window is open you can give the task a name that makes sense (such as DIMES).



Change User or Group... should be changed to SYSTEM and Run with highest privileges must be ticked. UAC blocks DIMES from running because it needs higher privileges to create raw sockets in order to ping.

Next select the Triggers tab and click on New...



From the Begin the task drop-down select At startup.

Enabled should already be ticked but make sure it is and click OK.



Next select the Actions tab and click on New...



Select Start a program from the Action drop-down.

Click Browse... and navigate to the DIMES Agent executable.

Click OK.



That should be it! There are other options you can play with if you need to but once you're done click OK.



Now all you need to do is start it by selecting Run from the Actions menu.



You can check that the DIMES Agent is running by looking at the Task Manager (you'll need to click on Show processes for all users as it will be running under the SYSTEM account).



Or by checking your account statistics, although these take a little while to update.

If you're pedantic, like me, you could always use Wireshark to make sure the pings are going out.