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Questions tagged [ethernet]

Ethernet is a set of networking technologies widely used to interconnect computers.

Ethernet is a set of networking technologies widely used to interconnect computers at the physical (layer 1) and link (layer 2) levels. The capability of Ethernet has matured to the point where it is used for both basic desktop computer networking and for carrier-grade networks where operators must guarantee quality of service.

More information at http://en.wikipedia.org/wiki/Ethernet

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Why is the minimum ethernet frame 64 bytes?

Perhaps this is better to ask an electronics engineer because it might have to do with something at the physical layer rather than programming. But we all user ethernet, and I know that the minimum frame size is 64 bytes but I've never bothered to…
dave
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Pymodbus Read/Write Floats (REAL)

I have modbus mapping setup in my AB Micro820 PLC. I have an array in 40001 for writing, and one in 42001 for reading. Both are 200 elements and REAL type (32-bit float). I can write and read currently, so I know the code works, just incorrectly.…
xinthose
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Arduino Display Ethernet.localIP()

I'm trying to assign the IP Address of the device to a String variable. When I use Serial.println(Ethernet.localIP()) to test it displays the IP Address in octets. If I use String(Ethernet.localIP()); then it displays it as a decimal. Is there a…
Pete
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How to test if link is up in bash script

using this script I am trying to detect if there is a network link. I am failing in putting multiple commands in one line (ethtool...). What to do? #!/bin/bash COMMAND="( /sbin/ethtool eth0 ) | ( /bin/grep \"Link detected: yes\" ) | ( wc -l…
ElkeAusBerlin
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How to know whether Android is connected to WiFi or ethernet?

How to know whether I'm connected to WiFi or ethernet in Android? In Android OS this is notified for thess icons Does it exist a way to know it programmatically?
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How can I access netstat-like Ethernet statistics from a Windows program

How can I access Ethernet statistics from C/C++ code like netstat -e? Interface Statistics Received Sent Bytes 21010071 15425579 Unicast packets 95512 …
Dénes Tarján
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Direct connection between laptop and arduino via ethernet

I made a project with the Arduino and the ethernet-shield. The Arduino is hosting a website which I can open via the browser on my laptop. The Arduino is connected to the router via ethernet. All of this works just fine. Now I have to present this…
derwahre_tj
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How to simulate 30Kbps Network link

I am developing C#/.NET application and at production site we have some exotic 30Kbps Ethernet network link. I am testing my app on network card 100Mbps and all works, but is seems some queuing behaves differently on slow links. How do I set my…
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send/receiving raw ethernet frames

I've to write an application on Linux that has the requirement to talk with a device with custom Ethernet type. There are many solutions even in SO how to write such an application. A drawback is that for this root access is needed (AFAIK).…
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Throttling Bandwidth on Ethernet Port

I'm writing an application to run on a server where I need to be able to set the maximum bandwidth for each Ethernet port (there will be up to 6 ports). Obviously I can throttle the bandwidth that my application uses but I haven't yet found any…
DawnMage77
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Why are there differences between ETH_P_IP and ETH_P_ALL when doing a read()

I have the following setup: client(eth0) --- (eth2) linux bridge (eth1) --- (eth1) server When I open a RAW socket on the linux bridge using fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); I have the socket bound to eth2. When the client sends…
A G
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How do I send a raw ethernet frame in python?

I need to have a project done in a few days, its a basic client and server interface. The catch is that it needs to be all raw sockets. I have no problem with creating that, I am just stuck on sending the packets. First I tried to bind it to an…
Noah Koster
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In OSI Networking Model, why is Network layer above Data-link layer

I always had a feeling that in OSI, the Data-link layer and the Networking layers should switch places because overall, the layers in the model seem to move from the user specific (Application layer) towards network specific (physical layer). Now,…
user1064539
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Prosilica GigE camera with OpenCV/python

I'm using a GigE (ethernet) prosilica GC camera on Mac OS X, and have been able to read it out through the proprietary sample viewing software from Allied Vision. I would like to be able to read out the camera using OpenCV. I have opencv installed…
Mike
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Minimal TCP/IP overhead (over Ethernet frames)

How small is the smallest frame size in Ethernet? What is the TCP and IP protocol overhead? What I want to find out is the overhead of a single byte TCP/IP stream in terms of used bandwidth (one way, excluding the ACK). I assume it is in the…
Jack Wester
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