Does anyone have a good suggestion on how to test if a network jack is live and getting DHCP with...

[G+_Brian Ward]

Does anyone have a good suggestion on how to test if a network jack is live and getting DHCP without plugging in a computer?

Sometimes I need to verify several jack in different locations but do not want to carry around my laptop. I was wondering if there is a way to use a arduino with a ethernet shield and maybe a display to show the IP address. Also needing it run off a battery.

 

Thanks

[G+_Ben Reese]

Arduino with ethernet shield probably would work. Seems like it took a while to get an IP where Padre was demonstrating though.

 

Raspberry Pi with a screen, or Android device with a USB ethernet adapter may be better. Or it's possible the KH router was just being stupid at the time.

[G+_Bob Clingan]

There are definitely some networking tools that do this, but cost several hundred to almost $1k, I would think you may be able to do something simple like you are thinking.

[G+_Benjamin Webb]

plug in wifi access point wirelessly connect with computer. Can turn a PI into one if you have one laying around.

[G+_Black Merc]

Sounds like he wants a diy version of the commercial tool that padre' used in the networking 101/102 episodes. That tool had many functions that I think even a pi could not do... You have to admit, the commercial unit was worth the money.

[G+_Benjamin Webb]

Guys he just asked to check if the jack was live with DHCP. He said nothing of performing a wireshark and even then I don't think that unit was battery powered.

[G+_Brian Ward]

Thanks for the comments. I am looking for a simple tool to test DHCP and is battery powered. I have never programed before and was not sure if this would be difficult to do with an arduino.

[G+_Giligain I.]

• this is a bit different direction, but pointing in right direction.

 

ESP-8266 WiFi.config(ip, gateway, subnet);

https://github.com/esp8266/Arduino/issues/2371

 

Step 2:

Print out dynamic IP (easiest). Print out the IP address of your device to a serial port using WiFi.localIP(): Serial.println(WiFi.localIP()). Obviously this is only useful if you have a wired serial connection, but it's also the easiest.

[G+_John Sullivan]

Please consider this: You're walking around a building testing network jacks with an Arduino, RaspPi or laptop and you find one that doesn't work. What do you do now? Those devices only tell you if you can get a connection or not, but not what the problem might be.

 

If you have a properly wired network jack connected to a device that can function as a DHCP server and use that jack to connect to a computer - like device, the computer will get an IP address.

 

Really what you want to test for is whether the network jack is physically wired correctly, with all wires in the correct places and no shorts or opens. I would suggest you look at some of the network wire testing tools, which can actually tell you if a wire is not connected correctly, and which one.

 

Network jacks and wiring are physical entities ... once you have determined that the jack is wired correctly, any computer device that you connect to it will get assigned an IP address by the DHCP server. If it should not, the problem is not with the jack.

[G+_Ben Reese]

I guess it depends on what you're trying to accomplish. If you're trying to find out if a jack is wired properly and getting DHCP, a Raspberry Pi or Arduino ethernet shield won't necessarily be enough. If you know all your jacks are wired properly and you just want to know what's connected to a switch/DHCP server, a Raspberry Pi or Arduino should be fine. Both of these will presumably be 100BASE-TX - therefore only using 2 pairs. Fine if you just want to test connectivity, but insufficient if you want to test all 4 pairs.

 

Really, the Raspberry Pi would probably be easier if you also get a battery powered hdmi display. A simple script to run ifconfig every 2 seconds is all you need.

 

An Arduino with a small display would be a fun project and probably not too difficult if you can copy/paste/tweak the code.

[G+_Scott Dible]

Maybe this is crazy... but what about using a USB ethernet adapter and an Android phone? I believe you can get them in micro USB or USB C. Shouldn't be hard to test the connection if it works. I think I might have hardware around that I could test it...

[G+_Giligain I.]

I have never programed before and was not sure if this would be difficult to do with an arduino.

 

• based on this comment, may I suggest another alternative without coding–not that I'm discouraging that.

 

• I see (2) hardware pieces needed, no make that (3):

1) USB battery pack

2) your phone (a phone) with working Wifi — install app: Fing Scan, secure, manage and troubleshoot any network.

https://www.fing.io/

3) Vonets VAP11G-300 the Mini WiFi repeater

http://www.vonets.com/ProductViews.asp

 

4) computer not needed at site locations, but required for initial setup.

 

• from here the answer may fork, but here is a start:

1) the setup of Vonets...this is where I don't know what you are needing exactly, but this device does the hardware hookup for you, it's up to you to make I a bridge or not, repeater or not, dynamic or static (if static then the router, if any, will assign DHCP)

2) power Vonets with USB and connect to network you created using phone running the Fing app. The app will provide all the network info you need.

3) this is assuming you don't need internet access. If false, then a computer is required at site for Vonets setup to login to existing network...and then repeat setup via the Web page interface.

4) if Vonets is plugged into the working jack in question, then your setup will finish the rest to provide details.

5) go back to programing and learning about the Arduino or RasPi or what have you for next project or improve this one.

Cheers

[G+_Giligain I.]

• this is how I used the Vonets bridge/repeater..and I love it!

From my collection:

https://plus.google.com/110690680341063574122/posts/VbbkDuz3boP

[G+_Scott Dible]

Brian Ward I was able to do this on my Android phone pretty simply. There was a caveat... I have an older OnePlus One, so I had to plug the usb network adapter into a powerd hub. I'm guessing that wouldn't be a problem with a newer USB C powered device. If you have a micro USB device, they make network adapters that also have a USB A for power (you could plug it in to a portable battery).

 

As soon as I plugged it in, it connected to my network and I was able to scan the network using a variety of tools. My tool of choice (Fing) didn't work because it only wants to use WiFi. It was easy to find other network tool apps though. Pretty cool actually.

 

This solution would be easy and inexpensive.