Rename network interface linux

ifrename

You configure this userspace program writing the configuration file /etc/iftab :

The good thing of this program is that you can select intefaces by the name of the kernel module, by MAC address, by bus position and other methods. But beware that the standard Debian startup of ifrename runs the program once, when all the interfaces are already discovered and named. In this case it is not possible to swap two interface names, because when you try to rename the first interface, an error occurr: Error: cannot change name of eth1 to eth0: File exists .

Debian 8 Jessie

The udev cache file is named now /etc/udev/rules.d/70-persistent-net.rules , sometimes only one Ethernet card is automatically added to this file, some other times the cache file is not created at all.

To force the creation of that file just execute the command:

Debian 9 predictable network interface names

Esempio: enp3s0f1

Per disabilitare questa funzione, chiamata Predictable Network Interface Names è possibile aggiungere l’opzione kernel net.ifnames=0 ad esempio in /etc/default/grub , opzione GRUB_CMDLINE_LINUX.

Se è installato la helper utility di udev chiamata biosdevname, è opportuno passare al kernel anche il parametro biosdevname=0.

Источник

Change Network Interface Name: eth0,eth1,eth2+

The best way to rename a network interface is through udev .

Edit the file /etc/udev/rules.d/70-persistent-net.rules to change the interface name of a network device.

The names of the network devices are listed in this file as follows:

Rename network interface from eth0 to wan0

To rename interface eth0 to wan0 , edit /etc/udev/rules.d/70-persistent-net.rules file and change NAME=»eth0″ to NAME=»wan0″ .

For Centos/RHEL etc.

Rename the network interface configuration file:

Edit the network interface configuration file and replace all occurrences of the old name eth0 with the new one wan0 :

For Ubuntu etc.

Edit the /etc/network/interfaces file and replace all occurrences of the old name eth0 with the new one wan0 :

Test changes

Reboot the system to test changes:

Verify new settings:

Rename network interface from eth1 back to eth0

Q: Why does my network interface name change?
A: The interface name of a network device increases if the MAC address of a network card changes.

Edit the file /etc/udev/rules.d/70-persistent-net.rules .

Copy the new MAC address from eth1 to the line of your eth0 rule.

Delete the rule for eth1 . Save and close the file.

For Centos/RHEL etc.

Check the network interface configuration located under:

Don’t forget to replace the old MAC address with the new one.

For Ubuntu etc.

Make sure /etc/network/interfaces file has correct configuration:

Источник

Rename Network Interface using Udev in Linux

udev is a daemon which dynamically creates and removes device nodes from /dev/, handles hotplug events and loads drivers at boot time. It replaces the hotplug package and requires a kernel not older than 2.6.12.udev – /dev/ and hotplug management daemon

Install udev in Debian

#apt-get install udev

After installing this you need to reboot your machine.

Upgrade from devfs to udev on Debian Sarge

Some of you used devfs under Woody, or under their previous Sarge install. When going kernel 2.6, it may be useful to revert or upgrade to udev instead. The problem is that their nomenclatura is different, so your system may be rendered unbootable. Let’s see what to care about to switch from devfs to udev.

First, the bootloader will no longer need the devfs=mount parameter on the kernel command-line. So, wheter you use GRUB or LILO, remove or comment the reference to devfs=mount.

Second, check in your /etc/fstab that you have nothing in devfs-nomenclatura, like /dev/ide/host0/bus0/target0/lun0/part3, but everything in the standard nomenclatura like /dev/hda3.

Third, install the udev package, it will probably bring some dependencies too. That’s ok.

Last, check the links in /etc/udev/rules.d/. There are probably two links to the upper directory: compat-full.rules and devfs.rules. Remove them and create a new link to udev.rules and to cd-aliases.rules like this

# cd /etc/udev/rules.d/
# rm compat-full.rules devfs.rules
# ln -s ../udev.rules .
# ln -s ../cd-aliases.rules .

Now, reboot, and if you want, remove package devfsd.

Note: It may also be necessary to reconfigure some special packages which store device information in their configuration file, like XFree86.

If you want rename a network interface’s device name when using udev. This can be practical to do since the automatically assigned device name may actually change around a bit due to random variation in the initialisation process of them.

For instance, eth0 can on one bootup refer to network interface A and eth1 to network interface B, but on another bootup can interface A be assigned eth1 and interface B be assigned eth0, which can cause problems if only one of them has a network cable attached and is configured to obtain an address over DHCP — the interface without the cable attached will then attempt to do that instead!

udev Overview

Unlike the traditional Linux system, where the device nodes in the /dev directory have been a static set of files, udev dynamically provides only the nodes for the devices actually present on a system. Although devfs provided a similar functionality, advocates for udev cited a number of reasons for preferring its implementation over devfs.

udev supports persistent device naming, which does not depend on, for example, the order in which the devices are plugged into the system. The default udev setup provides persistent names for storage devices. Any hard disk is recognized by its unique filesystem id, the name of the disk and the physical location on the hardware it is connected to.

udev executes entirely in user space, as opposed to devfs’ kernel space. One consequence is that udev moved the naming policy out of the kernel and can run arbitrary programs to compose a name for the device from the device’s properties, before the node is created.

udev operation

Udev is a generic kernel device manager. It runs as a daemon on a Linux system and listens to events the kernel sends out if a new device is initialized or a device is removed from the system. The system provides a set of rules that match against exported values of the event and properties of the discovered device. A matching rule will possibly name and create a device node and run configured programs to set-up and configure the device. Udev rules can match on properties like the kernel subsystem, the kernel device name, the physical location of the device, or properties like the device’s serial number. Rules can also request information from external programs to name a device or specify a custom name that will always be the same, regardless of the order devices are discovered by the system.

Obtaining the MAC addresses from your Debian machine

If you want to obtain MAC address of any linux machine you need to run the following command

This will give you all the existing network interfaces in your machine

# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:AB:CD:12:34:56
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:3
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:180 (180.0 b)
Interrupt:185 Base address:0xc000

In the above example HWaddr is your MAC address 00:AB:CD:12:34:56

Using udev

Basic Rules

udev provides several different match keys which can be used to write rules which match devices very precisely. Some of the most common keys are introduced below, others will be introduced later in this document. For a complete list, see the udev man page.

KERNEL – match against the kernel name for the device

SUBSYSTEM – match against the subsystem of the device

DRIVER – match against the driver name for the device

After you have used a series of match keys to precisely match a device, udev gives you fine control over what happens next, through a range of assignment keys. For a complete list of possible assignment keys, see the udev man page. The most basic assignment keys are introduced below. Others will be introduced later in this document.

NAME – the name that shall be used for the device node

SYMLINK – a list of symbolic links which act as alternative names for the device node

Create a new file in the udev rules directory, e.g. /etc/udev/rules.d/010_netinterfaces.rules

In it specify the renaming in the following way for each interface on its own line

KERNEL=”oldnameprefix*”, SYSFS