11.9. Troubleshooting Network Device Naming
~]#where ifname is one of the interfaces listed by the following command:
udevadm info /sys/class/net/ifname | grep ID_NET_NAME
/usr/lib/udev/rules.d/60-net.rules- from initscripts,
/usr/lib/udev/rules.d/71-biosdevname.rules- from biosdevname,
/etcand edit the file appropriately. In other words, comment out or arrange schemes to be used in a certain order.
Example 11.1. Some Interfaces Have Names from the Kernel Namespace (eth[0,1,2...]) While Others Are Successfully Renamed by udev
Example 11.2. In /var/log/messages or the systemd Journal, Renaming Is Seen to Be Done Twice for Each Interface
initrdimage are likely to encounter this issue. The interface name is initially assigned (through biosdevname or udev or dracut parameters on the kernel command line) during early-boot while still in
initrd. Then after switching to real
rootfs, renaming is done a second time and a new interface name is determined by the
/usr/lib/udev/rename_devicebinary spawned by udev because of processing 60-net.rules. You can safely ignore such messages.
Example 11.3. Using Naming Scheme in ifcfg Files with ethX Names Does Not Work
- The system has only one network interface.
- When used for virtio NICs in Red Hat Enterprise Linux 7 virtual machine guests. See the KVM Paravirtualized (virtio) Drivers and Network Configuration chapters in the Virtualization Deployment and Administration Guide
Example 11.4. Setting net.ifnames=0 Results in Inconsistent enpXxX Names
systemdpredictable interface naming (
net.ifnames) and biosdevname naming schemes are disabled, network interfaces continue to use the unpredictable and potentially inconsistent ethX name originally given by the kernel.
systemdpredictable interface naming scheme or the biosdevname naming scheme to rename the kernel unpredictable ethX interfaces in a predictable way to a name which is always consistent across reboots.
Example 11.5. Limitations for Prefixes of Ethernet Interfaces
- It consists of ASCII characters.
- It is an alpha-numeric string.
- It is shorter than 16 characters.
- It does not conflict with any other well-known prefix used for network interface naming, such as