refers to the wired style to connect a bunch computers or a way to connect to such network. This tag is for both software and hardware part of this issue.

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20
votes
2answers
27k views

How can I create a virtual ethernet interface on a machine without a physical adapter?

I have a Dell XPS 13 ultrabook which has a wifi nic, but no physical ethernet nic (wlan0, but no eth0). I need to create a virtual adapter for using Vagrant with NFS, but am finding that the typical ...
11
votes
1answer
4k views

what level of the network stack does tcpdump get its info from?

As I was trying in vain to fix a faulty ethernet controller here, one thing I tried was running tcpdump on the machine. I found it interesting that tcpdump was able to detect that some of the ICMP ...
11
votes
1answer
3k views

Why my ethernet interface is called enp0s10 instead of eth0?

Just that, when I run ifconfig -a I only get lo and enp0s10 interfaces, not the classical eth0 What does enp0s10 means? Why is there no eth0?
10
votes
2answers
4k views

Solving Ethernet watchdog timer deadlocks

I have a debian linux box (Debian Squeeze) that deadlocks every few hours if I run a python script that sniffs an interface... The stack trace is attached to the bottom of this question. ...
9
votes
2answers
12k views

changing the names of network interfaces, debian wheezy

I'm trying to set a name for an interface, "ethLan" instead of eth0. Doing so also ensures that the if's name will remain consistent at every reboot and kernel. I did find some articles in the ...
9
votes
1answer
955 views

Send a packet over the network even when its target is the local host

Under Linux if you send a packet to the address of one of its network interfaces, this packet is routed internally, it is never sent over the network. That's the right thing in 99.99% of the cases. ...
8
votes
2answers
316 views

“Pipe” Wi-Fi signal through Ethernet cable

Currently the Ethernet ports in the building I work in are down, but the Wi-Fi works. I have a Wi-Fi-enabled laptop (Ubuntu 14.04 LTS (Trusty Tahr)) and a non-Wi-Fi enabled workstaion (Debian 8 ...
8
votes
2answers
3k views

How can I disable TCP/IP for an Ethernet adapter?

I have CentOS 6.3 running in a (virtual) machine with two Ethernet adapters. I have eth0 connected to a TCP/IP LAN and eth1 connected to a DSL modem. The system is intended as a dedicated ...
8
votes
2answers
40k views

CentOS 6.3 Device eth0 does not seem to be present (Minimal non-cloned setup)

I installed CentOS 6.3 on my hardrive partition (new install...minimal install). After successful installation, I see that eth0 was down. I looked for this file: ...
7
votes
2answers
2k views

Identical MAC address on two different VM, yet I have internet connectivity

I have set up a network as such: Set up host-only networking on VirtualBox. The first adapter is configured with NAT, the second with host-only networking HOST: Windows GUEST: CentOS VM1, CentOS VM2 ...
7
votes
2answers
22k views

Check whether network cable is plugged in without bringing interface up

I am trying to identify NICs on ~20 remote servers (2-6 NICs on every server). To begin with, I want to identify those ready for use and free ones. How can I check the state of the physical media? I ...
6
votes
3answers
2k views

Print mac address to file

With a bash script, can I read the mac address of my eth0 and print it to a file?
6
votes
2answers
802 views

How can I test the current carrier state for an ethernet adapter in Linux?

In Arch Linux, how can I check if a network device (say eth0) has a carrier signal present?
6
votes
1answer
521 views

2 IPs on 1 ethernet adapter

I'm trying to get 2 ethernet adapters to work. The first one, eth0, works out of the box. The second one, eth1, acts weird. This port uses the LAN9512. This is my /etc/network/interfaces file: auto ...
6
votes
1answer
9k views

Determine ethernet speed in RHEL 6

How to check whether eth0 has connection speed 10Mbit, 100Mbit or 1Gbit? I tried ethtool, but it says No data available. I also tried dmesg | grep -i duplex and it's empty. [root@dioptase ~]# lspci ...
6
votes
1answer
7k views

Using the Wifi of a notebook via ethernet for another PC

I want to connect a PC to the internet via my notebook, which is connected to a WLAN. The setup should look like the following scheme: PC (eth0) -> Notebook (eth0) -> Notebook(wlan0) -> ...
5
votes
2answers
3k views

How to check programatically if the Ethernet cable is plugged in?

As you know, in Windows, when we plug in the network cable, the network symbol will change to another status. How can I know whether the cable is plugged in or not via the command prompt in Linux?
5
votes
3answers
12k views

RHEL: Creating stable names for network interfaces

We have a RHEL 5.5 box with 8 interfaces. And the eth interface naming is flip flopping. Sometimes eth0 comes up on physical port 7th, and sometimes on another physical port. We want the naming to ...
5
votes
1answer
3k views

How can I most simply transparently bridge traffic between wlan0 and eth0?

I am looking to do this on a Raspberry Pi, but I don't mind which operating system I have to install, so the easiest most out-of-the-box solution for Pidora (Fedora 20 Remix), Raspbian (Debian) or ...
5
votes
1answer
774 views

Ethernet adapter stuck at 10 Mbit/s

My Ethernet adapter is somehow stuck at 10 Mbit/s. Here's the output of ethtool eth0: Settings for eth0: Supported ports: [ TP MII ] Supported link modes: 10baseT/Half 10baseT/Full ...
5
votes
1answer
8k views

serial data over ethernet on a linux box

I'm trying to connect a widget (192.168.1.214:20108) through Ethernet (serial to Ethernet) to a Linux box. Under Windows using a virtual device driver mapping I can see the serial data, so I know ...
5
votes
3answers
2k views

Find out if computer started via Wake-on-LAN or power button?

Is there any (reliable) way to find out if the PC booted because of a Wake-on-LAN Packet instead of pressing the power button? I want automatically check if WOL is correctly configured. I know about ...
5
votes
1answer
1k views

What's the difference between the drivers r8169 and r8168?

Realtek provides the source code for the r8168 driver which is based on the r8169 driver from the kernel tree if I may believe their source: /* * This driver is modified from r8169.c in Linux kernel ...
4
votes
1answer
10k views

What is the difference between virbr# and vnet#?

I am running KVM on RHEL6, and I have created several virtual machines in it. Issuing ifconfig command to the host system command line shows a list of virbr0, virbr1... and vnet0, vnet2... Are they ...
4
votes
2answers
5k views

ethtool get permanent MAC address returns all 0's

I need to read permanent (burned-in) MAC address of network adapter. Since MAC address can be easily spoofed, I need to read the real one which is written on EEPROM. I need to do it using C++ on ...
4
votes
2answers
4k views

Replacing identical NIC cards creates eth1 instead of using eth0 in Ubuntu

I changed out a NIC card that was the exact same make and model. The setup process for Ubuntu 11.04 was very seemless and easy so I figured it would be smart enough to setup up the replacement card. ...
4
votes
3answers
3k views

How do I share an internet connection through USB?

I have two Linux boxes. One is running KNOPPIX and the other Ubuntu. I have only one wifi dongle between them, and only one of them has an Ethernet port. They both have free USB ports however. I ...
4
votes
2answers
10k views

No wired ethernet connection

I'm using elementary OS (based on Ubuntu 12.04) and yesterday I woke up to no wired ethernet connection. As far as I can remember I changed absolutely nothing, it was working at night and not anymore ...
4
votes
2answers
452 views

What happens when I plug a Ethernet cable?

What happens when I plug in a Ethernet cable? I want to be able to see what's happening on the Level 2/3 (I believe the protocols I'm trying to watch is Ethernet, IP (v4 and v6) and DHCP for IP ...
4
votes
2answers
6k views

How do I configure which ethernet connections are active on boot?

I have an unmanaged dedicated server that I administer, running CentOS. Recently when I reboot the server, I am unable to use SSH. Both times this has happened the server host has determined the issue ...
4
votes
1answer
1k views

How can I update the OUI list used for Netdiscover?

Netdiscover keeps showing a lot of "Unknown vendor" devices, when I generally can find the vendor pretty quickly via Google. Is there any way to manually update whatever OUI list Netdiscover uses?
4
votes
1answer
16k views

How To Diagnose Faulty (onboard) Network Adapter

I'm looking for advice on diagnosing ethernet connectivity issues under Linux. I suspect it's a hardware issue, though I am not entirely sure. It's an nVidia chipset and ethernet adapter. The device ...
4
votes
1answer
3k views

eth0 is proxy-arping, but /proc/sys/net/ipv4/conf/eth0/proxy_arp is 0

I'm scratching my head about this question... I have a debian squeeze machine that is connected to an internal lab network. We have a lot of machines that have default proxy-arp configurations on ...
4
votes
2answers
1k views

802.3ad on FreeBSD and Linux using crossover cables?

I have setup a NFS server on FreeBSD 8.1, which will be serving one Linux client. Each box has a dual-port 1gig fiber card, and each box is directly connected to the other over this link. There is ...
4
votes
2answers
408 views

Linux network stops functioning after random time (wired)

I'm unsure if this is hard or software issue but I really need to find out. I was running Windows 8.1 for some time, then swapped to Linux mint with kernel 3.13 which worked fine. I updated kernel to ...
4
votes
2answers
676 views

Send traffic to self over physical network on Ubuntu

I have a dual port ethernet NIC and let's say I have connected both ports in a loop and assigned the following IPs to the 2 ethernet interfaces: eth2 -> 192.168.2.1 eth3 -> 192.168.3.1 I want to ...
4
votes
3answers
19k views

Can't connect to to internet. Debian Wheezy, pinging DNS address works

I have booted Debian Wheezy from SD card on a Beaglebone Black board. Version: debian-wheezy-7.0.0-armhf-3.8.13-bone20.img.xz, from http://www.armhf.com/index.php/download/ I have set up my ...
4
votes
1answer
1k views

difference tun/tap, is the interfaces that handle protocols or the OS?

I have difficulties to understand difference between tap and tun interface. I know it is an often asked question and I apologize for that. I asked the same questions on stackoverflow and someone told ...
4
votes
1answer
146 views

How do you ensure physical network interfaces always get the same interface name across reboots on an embedded Linux system?

For an embedded Linux system, if I have two or more network interfaces, how do I ensure that they always get the same interface names every boot In other words, I want, for example, eth0 to always ...
4
votes
0answers
185 views

Ethernet bonding round-robin not work when 1st interface down

I'm trying to understand the bonding mode=0 (load balancing round-robin). Using eth0 & eth1, I created bond0 interface as the configuration below : root@test-env1:~# cat ...
4
votes
1answer
68 views

How best to enable end-user configuration of wifi or Ethernet on embedded device?

I'm building a device that includes an embedded Linux computer and I need to allow the device user to (easily) configure the device to connect to their wired or wireless network. I know there are ...
3
votes
4answers
10k views

Transfer files between Windows and Linux machines?

My problem is that I need to backup the files on my Linux machine to my Windows laptop. My external hard drive died, and so backing up to an external drive is out of the question for the time being. ...
3
votes
2answers
1k views

Wait for ethernet cable plug-in/plug-out event under Linux?

I know that I can poll the link state via the SIOCETHTOOL/ETHTOOL_GLINK ioctl but this would require to endlessly request the state. The same goes for parsing /var/log/messages. So my questin is, is ...
3
votes
2answers
340 views

Ethernet Sniffing Embeded Device

I recently dug out some prototyping equipment from the trash and I want out figure out what the heck it is. It has a port labelled 'Ethernet' and when I plug it into a router the lights flash like its ...
3
votes
1answer
207 views

How to tell if two ethernet interfaces are on the same lan?

I have to secure interfaces on Linux servers by setting bonding interfaces. The cabling information is not accurate. Is there a simple way to know if two interfaces are connected to the same LAN? ...
3
votes
1answer
164 views

Linking Ethernet interfaces

I'm quite new to Linux networking. I have a Debian PC with two Ethernet interfaces, one embedded on the motherboard and another on a PCI card. The first one, let say eth0 is connected to my router ...
3
votes
2answers
540 views

PPC Debian: eth0: switching to forced 10bt / 100bt

I recently installed debian on an old G4 iMac, and everything is working fine except that the console is constantly spammed with alternating eth0: switching to forced 10bt eth0: switching to forced ...
3
votes
1answer
2k views

How to do mac spoofing on Linux Mint 17?

How to do mac spoofing on Linux Mint 17? Through macchanger -a I've tried to changemy mac address but new mac id doesn't authenticates successfully. pppd gives successful authentication message only ...
3
votes
1answer
5k views

multiple default gateways for alias interfaces (SOLVED)

Alias interfaces defined in /etc/network/interfaces cannot have multiple default gateways. Unfortunately I would like to use the same interface to access 2 different nets, and I need to define 2 ...
3
votes
1answer
2k views

Bonds vs. Aggregators

I'm almost to the point where I can post the solution I wound up with for my complex port bonding question. However, in reading the bonding.txt file, I see this option text: ad_select Specifies the ...