The Stack Overflow podcast is back! Listen to an interview with our new CEO.
103

Setting up a dummy interface If you want to create network interfaces, but lack a physical NIC to back it, you can use the dummy link type. You can read more about them here: iproute2 Wikipedia page. Creating eth10 To make this interface you'd first need to make sure that you have the dummy kernel module loaded. You can do this like so: $ sudo lsmod | ...


86

Answer on "What does enp0s10 means?" question: enp0s10: | | | v | | en| | --> ethernet v | p0| --> bus number (0) v s10 --> slot number (10) Source: udev-builtin-net_id.c on GitHub


56

That's a change in how now udevd assigns names to ethernet devices. Now your devices use the "Predictable Interface Names", which are based on (and quoting the sources): Names incorporating Firmware/BIOS provided index numbers for on-board devices (example: eno1) Names incorporating Firmware/BIOS provided PCI Express hotplug slot index numbers (...


41

Network interfaces can be named anything, so no matter what you do, you'll run into situations where (1) there is a "physical" network interface with a name that didn't match your pattern, or (2) there is a "physical" network interface that will match your pattern. On top of that, if I was a user of your tool, the moment your tool wouldn't allow me to do ...


28

For systemd predictable interface names, the prefixes can be seen in udev-builtin-net_id.c : * Two character prefixes based on the type of interface: * en — Ethernet * ib — InfiniBand * sl — serial line IP (slip) * wl — wlan * ww — wwan so for both the traditional ethX style of naming and the newer systemd naming, an initial letter e should be an ...


26

You can create virtual interfaces using the iproute2 toolkit. ip link add veth0 type veth peer name veth1 This will create 2 interfaces, veth0 and veth1. Think of them as 2 ends of a pipe. Any traffic sent into veth0 will come out veth1 and vice versa. If you want the traffic to be routed, you can do: sysctl -w net.ipv4.conf.veth0.forwarding=1 This will ...


18

Those are network interfaces, not IP addresses. A network interface can have packets from any protocol exchanged on them, including IPv4 or IPv6, in which case they can be given one or more IP addresses. virbr are bridge interfaces. They are virtual in that there's no network interface card associated to them. Their role is to act like a real bridge or ...


18

Those are interface's flags. They are documented in the netdevice(7) man-page. Below is the relevant part (reordered alphabetically): IFF_ALLMULTI Receive all multicast packets. IFF_AUTOMEDIA Auto media selection active. IFF_BROADCAST Valid broadcast address set. IFF_DEBUG Internal debugging flag. IFF_DORMANT Driver signals ...


17

The articles you found are somewhat outdated. There is now an easy method to assign names to network interfaces, through Udev. On Debian and derivatives (including Ubuntu), look out for a file called /etc/udev/rules.d/70-persistent-net.rules. This file is created by /lib/udev/rules.d/75-persistent-net-generator.rules with the help of the script /lib/udev/...


17

Yes, as I have done this before, but with Ubuntu-based distros connected to Windows Vista. However this should still work with Windows 10. This is called a direct ethernet connection. There are a few steps to this: Windows, p1 check current IP for example Start, cmd to open a terminal, run ipconfig write down the current IP(s) to compare later Both ...


15

This is one of those things that surprises people because it goes against what they've been taught. 2 machines with the same hardware mac address on the same broadcast domain can talk to each other just fine as long as they have different IP addresses (and the switching gear plays nice). Lets start with a test setup: VM1 $ ip addr show dev enp0s8 3: enp0s8:...


14

The 2 methods I've seen used predominately are to use ethtool or to manually parse the contents of /sys. ethtool For example if your interface is eth0 you can query it using ethtool and then parse for the line, "Link detected". Example $ sudo ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full ...


14

Do NOT use mii-tool. It was last updated years ago and does not support anything over fast ethernet. There are few ways you can determine ethernet speed. The most recommended one is cat /sys/class/net/<interface>/speed The output will be 10, 100, 1000, ...etc. In fact you can get almost all data you need about your network card from /sys/class/net//...


13

Yes. By putting network interfaces into promiscuous mode, tcpdump is able to see exactly what is going out (and in) the network interface. tcpdump operates at layer2 +. it can be used to look at Ethernet, FDDI, PPP & SLIP, Token Ring, and any other protocol supported by libpcap, which does all of tcpdump's heavy lifting. Have a look at the ...


11

It's pretty easy. You need to connect PC to notebook. Configure eth0 on PC (set for example ip = 192.168.2.3 and default gateway 192.168.2.2 and dns server to 8.8.8.8). That's all you need to do on PC. On notebook you need to set up the internet connection as usual and configure eth0 with the following way: set ip address to 192.168.2.2, enable net ...


10

There is a Linux-feature which makes your machine reply for every IP address assigned, on every interface, when they share the same IP subnet, regardless of the particular IP-interface assignments. This may or may not be desirable for you. This feature is switched on by default, and you can configure it through sysctl. For the output traffic, your machine ...


9

The r8168 driver is a classical vendor-provided out-of-tree driver, with all the benefits and problems that come with it. The Linux r8169 driver comes with your distribution kernel, has much broader hardware support, but is possibly slower to adapt for new hardware. On the other hand, it’s supported by the kernel people, who have rejected r8168 on the ...


9

cat /sys/class/net/eth0/carrier is by far the easiest method.


9

Each network interface will have it's own IP address if IP traffic is to flow through it. Take for example, your router/modem device that most homes and/or small offices have. There will a connection to your computers/laptops on the internal side of the router - whether that is WiFi or Ethernet. These are normally in the private address ranges of 191.168....


9

Yes, you can do this, and it's not even that hard. I have a laptop with a wireless card, and an ethernet port. I plugged a RapberryPi running Arch Linux into it, via a "crossover" ethernet cable. That's one special thing you might need - not all ethernet cards can do a machine-to-machine direct connection. The other tricky part is IP addressing. It's best ...


9

The naming convention is that LAN interfaces are named eth0, eth1, ... and that WLAN interfaces are named wlan0, wlan1, ... What you see are the so called "predictable names" that systemd introduced. In practice, they are anything but predictable, and they can even change when the hardware is changed, which is exactly the problem they are supposed to avoid. ...


8

Please do not get discouraged by the overwhelming amount of information in setting up of samba. It's pretty simple as discussed here. If you do not believe, these are the steps I did in my machine and it took me just couple of minutes to access the mount point of my RHEL machine on the Windows machine. I assume the RHEL and Windows machine are available in ...


8

Your networking devices are renamed to correspond with their location on the PCI bus. When you removed your GPU, your ethernet device changed from enp2s0 to enp1s0. In order to reconnect, you have a few options: Create profiles for enp1s0 that match those of enp2s0 Change the rules for naming devices to give this card a unique name, and edit your profiles ...


7

Check udev config files. A file like this: /etc/udev/rules.d/70-persistent-net.rules ties the NAME (ethX) to the Mac address. You probably have the old cards MAC tied to eth0. Remove its line and change the new card to eth0.


7

How about ifplugd? ifplugd is a Linux daemon which will automatically configure your ethernet device when a cable is plugged in and automatically unconfigure it if the cable is pulled. This is useful on laptops with onboard network adapters, since it will only configure the interface when a cable is really connected. (There is also netplugd, but it was ...


7

On Solaris 11: dladm show-phys On older releases: kstat -c net ":::link*"


7

Yes, given the following config: .-----------. .-----------. | Switch1 | | Switch2 | '-=-------=-' '-=-------=-' | | | | | | | | .-=----.--=---.---=--.----=-. | eth0 | eth1 | eth2 | eth3 | |---------------------------| | bond0 | '---------------------------' Where each switch has its two ...


7

I always suspect the cables long before I suspect the actual Ethernet NICs. They almost never fail! To methodically debug the issue I'd first eliminate the following things: Ethernet Cable Ethernet female connectors on NIC and switch Another device on the network using the same IP Once the above have been eliminated as potential problems then move up to ...


7

Each network adapter on linux has a sysctl boolean parameter accept_local (/proc/sys/net/ipv4/conf/eth0/accept_local). Try setting it to 0 for all adapters involved (additionally, you may need to modify your routing table to suit your test setup). Also, make sure that rp_filter (/proc/sys/net/ipv4/conf/eth0/rp_filter) is enabled (not 0). Reference: http://...


Only top voted, non community-wiki answers of a minimum length are eligible