Battery powered Ethernet link tester

Recently I was seconded to the Networking Team. In one of the days I was required to trace down a network port which was wrongly labelled. Luckily, I had my cable tracer with me, however the solution was not ideal. There were 8 possible ports and only one tracer.... I knew that 4 out of the 8 ports must be live. But which ones?

While having a mobile device like a laptop is helpful, carrying a laptop with you only for live port detection is far from ideal. I started to look for an alternative solution.

After a bit of research, I found a site where one of the users describes a process of converting a CentreCom 210 TS Tranceiver into a live port detector. The process is fairly easy, it involves some soldering and it requires a small switch and a battery.

Since I had no available transceivers, I started to look for a different solution using something that I have. Basically any small switch, hub or even a Raspberry Pi (quite an expensive solution for port detection) would do the job as long as the device has a link light and can be powered with 5 V. I had a look around the house and I found  a small USB print server that had a 5 V input. Great! Now the only thing needed was a 5 V power source. Obviously EBay had the solution and it does not need any soldering just a bit of electrical tape and double sided tape.

What you need:
- small USB  print server (I had a DLink DP-301U one but there are plenty others on EBay and Amazon, just make sure they have a 5 V power input)
- battery box holder (I've used this.)
- electrical tape
- double sided tape
- 4 AA batteries

The steps to create the port tested:

1. cut the power adaptor wire
2. take of the insulation for approx. 2 cm
3. take of the insulation for approx. 2 cm on the battery box
4. identify the + and - cables (most of the times the + is the internal part of the jack)
5. connect red to + and black to -
6. using double sided tape, tape together the print server and battery box, making sure that you will still be able to use the switch and you don't cover the MAC address
7. insulate the cables using the electrical tape
8. connect the cable to the print server
9. add the batteries
10.test the device

That's it.

And here is the result:

the size of the end device

End product in operation

Nexus 7 2012 - Rooting

It has been a while since I did not post anything. I was quite busy with other things.

I've recently bought a Nexus 7 3G 2012 and I've decided to root it as I do with all of my devices. However, I did not install any custom roms as I usually do. I like the original one and I do not see any reason why I would want to change that at the moment, it might change however soon.

I did quite a bit of research online and I found out that the easiest way to root the Nexus is with the Nexus Root Toolkit that you can find here: http://www.wugfresh.com/nrt/

I think that if you are able to follow straight ahead instructions, even if you are not a tech guy, you should be able to root your device.

There are many reasons to root a device, I specially need root in order to automate tasks with Tasker.

The New MAC mini has arrived

Hi everybody,

As I mentioned in my previous post, I have ordered a MAC mini to host my Servers. After a 2 days battle with Apple regarding delivery (and a really nice discount from them :) ), I've finally received the MAC and tried to install ESX 5.0 and 5.1. I've failed to install both of them, even with a custom image I was getting a PSOD.

As I do not give up things so easily, I decided to do more research and I've found the following blog post and a new ESX 5.5 image. 

http://www.virtuallyghetto.com/2013/09/running-esxi-55-on-apple-mac-mini.html

The image from the above link worked fine and it was very easy to install it. 

Before proceeding to install I have created a rescue USB drive and also an USB Mavericks install, just to be on the safe site if I do not manage to install ESX. 

In order to create the rescue USB I've used:  

http://osxdaily.com/2012/02/17/make-bootable-os-x-10-8-mountain-lion-usb-install-drive/

and to create the Mavericks installation USB  (I will try to use it later on to create a Virtual Machine as well) I've used: 

http://arstechnica.com/apple/2013/10/how-to-make-your-own-bootable-os-x-10-9-mavericks-usb-install-drive/

I've used the method with Terminal.

As an important thing to mention here, you will need to search the App Store for MAC OS Mavericks and download it instead of just click on Update. If you just click on Update, after the download the Mini will ask for restart without actually having an image file.

I have also downloaded the VSphere client (60 day Evaluation) and I have managed to connect to the ESX server, building one of the VMs right now.

So far the experience is really good...

The next step is to install Cisco Unity Call Manager.

Plans for the future

Hi everybody,

so I passed my CCNA at the beginning of September and went for a short holiday in Krakow (very nice city, recommending a visit if you have time).

After the above the new uni year has started so busy with installing PCs in a brand new building, deploying images and testing builds so not a lot of time, a lot of overtime but it was well worth it seeing the new students impressed by the facilities. After that I was seconded to the Networking team where I started to learn about Cisco Unified Communications Manager and now my plan is to get CCNA Voice certified. So far I managed to set up a Virtual Machine with the CUCM and I managed to install a Cisco IP Communicator with 2 lines and configure an Android phone with 3rd party SIP client. My next plans are to re-build my AD servers and connect them with CUCM.

I have also tried to configure my mobile phone and the CUCM server to run Cisco Jabber but the supported devices and Android OS versions are very limited and unfortunately no support for my Galaxy S2 with CyanogenMod.

As I like to do multiple things at the same time I had a quick look for a low power consumption server that could run my virtual machines (at the moment I am using them from my laptop but it is not ideal since I do not want to keep the laptop running all the time).

I did a bit of research and it looks like I will buy an Apple MAC mini. I wanted long time ago to start to study about ESX and get more into virtualisation so here we go.

I found a very interesting article about the subject:

http://www.virtuallyghetto.com/2012/12/running-esxi-50-51-on-2012-mac-mini-62.html

The posts in the future will be about: CUCM and getting the MAC mini setup.

If everything goes well I will order  the MAC on Monday so probably next week I will be busy :)

No updates at the moment, studying for ICND2.

Hi everybody,

There are no updates at the moment. I am studying for my Cisco exam. I will sit the exam at the beginning of September and hopefully I will have more time after. (not sure, it looks like I got the bug and I am already planning the next Cisco certification after the CCNA).

Posting plans for the future: Auto-login + periodic login to a WiFi network with idle timer and Web login,  SSH tunneling using a Raspberry Pi + Putty (useful in case you are connecting to the Internet from places that are not secure, personally I am using it to test access and user experience from an outside IP), creating a Virtual Machine from a running machine and many other subjects.

Thanks for your patience :)

Csaba

Wake Up PC by TEXT (SMS)

I was a bit busy with studying for my CCENT exam (I passed it on Friday), therefore there were not a lot of updates here.

Two weeks ago we have received a very good offer from SKY (free broadband+TV package) so we have decided to move to Sky. Here comes the problem. I cannot use Wake on WAN anymore. Well time to find a solution, and the solution was found. Wake by TEXT.

I had a spare Android phone (it reminds me of a discussion with an HP technician about not throwing away an Android phone and how I made him aware of Tasker. We had no broken PCs at work, so I did not get a chance to ask him how is he getting on with it. I will need to ask for his email address next time he is coming around). OK, that was off topic so the requirements are as follows:

- PC set up to Wake up on LAN and connected to the router through wire
- 2 android phones (one that will initiate the message and the second one which will stay at home connected to the same network as the PC)
- Tasker
- Wake on LAN

Configuration on the main phone that will initiate the process:

1. Install Tasker
2. Add a new task by taping the TASKS tab followed by +
3. Name the task "WAKE PC" and tap the check mark
4. Tap +, followed by Phone and Send SMS
5. Insert the "phone number" in the Number field, the number needs to be in international format (i.e. if in UK start with +44)
6. In the Message field add "PC" (without the quotation marks)
7. Tick Store In Messaging App if you wish the message to be saved
8. Create a Tasker Widget on the desktop named "Wake Up PC" and chose WAKE PC as task

Configuration on the second phone

1. Install Tasker and Wake on LAN
2. Start Wake on LAN
3. Tap Add New
4. Use the following details:

• Name: Home
• MAC: mac address of the PC
• IP or Domain: IP address of the network(ex 192.168.1.0)
• Port: 9 (if it does not work with 9 try 7)
• Send as Broadcast: ticked
• Subnet: 255.255.255.0 (if you are using a Class C address which most of the home networks use, it should be pre-filled)
• Packet Count: 5
• Interval(seconds): 1
• Tap Save

5. Start Tasker
6. Add a profile by taping +
7. Chose Event, Phone and Received SMS
8. Use the following settings:

• Type: SMS
• Sender: the phone number of the first phone
• Content: "PC" (without the quotation marks)

9. Add New Task by pressing +
10. Type in "WOL"
11. Tap +
12. Chose plugin followed by WoL, Wake On Lan Wan
13. Tap Edit and chose Home

Done. Time to switch off your PC and test it.

SMS forwarding using Phone Leash

Recently, I have changed my mobile phone service provider for an offer that cannot be refused. After approximately a month, I have noticed that I was not able to receive text messages from my family from abroad. The first step was to contact the provider and ask why suddenly, after one month the service has stopped working. After a couple of days they got back to me saying that the problem is not on their side and it was a weird thing for them as well. I have also contacted my family's provider and they were useless in sorting out the problem.

I was playing with the idea of going back to my previous provider but, I realized that it would not worth it, so I have decided to look for an alternative solution. After a short research, I concluded that SMS forwarding is the solution. I was thinking that Tasker might offer the service, but it was time consuming to find a way to reply to SMS' so I gave up the idea. I did a quick search on the Internet and I found Phone Leash which  was designed especially to offer the service that I needed. It is very easy to install it and set up.

It can be downloaded from:
https://play.google.com/store/apps/details?id=com.gearandroid.phoneleashfree&feature=search_result#?t=W251bGwsMSwyLDEsImNvbS5nZWFyYW5kcm9pZC5waG9uZWxlYXNoZnJlZSJd

It costs approx £2 but, it is well worth the money. I spare 30 pence on each SMS and I have already recovered the investment from the saving.

Once installed, there are two options:

1. Forward the SMS as SMS to a different number
2. Forward the SMS as email to an email address (in this case a data connection is necessary)

As extra options you have: Forward MMS, send notifications of low battery, set up SMS forwarding only for certain numbers and many more. 

As main advantages I could mention:

• easy way to reply to SMS', I just need to reply to the email
• a SMS' to my family costs only 10 pence compared to 40 pence with my current provider
• I can receive/reply to SMS' from the computer
• I can use the new number for online orders when I don't want to give out my real number (prevent spam)

As a main disadvantage, you need a spare phone that runs Android (it was not a problem for me since I always keep my old phone for testing).