Hi,

I am new to centos. I just install centos 7 server In my server i hav two Onboard NIC now when i start the server and put the command Ip a it shows eno1 and eth1 but when i reboot the server and put the command ip a it shows eno1 and eth0.

Please help me on that.

I think your talking about a bug in systemd that, renames network interfaces, for whatever bizarre reason(s).

Do you see any similar lines in your kernel log to the following?

1 members found this post helpful.

Welcome to LQ, ajoysys! &welcome back jsb; missed you!

LP doesn't 'do' "bugs". Period. Only *features*
Web-searching drowns me in possible keywords:
e.g.: https://fedoraproject.org/wiki/Featu...InterfaceNames (&worse!)
The concept is: what IF you add/move NICs? config files BREAK
(careful: is it en {oh,zero} 1: o/0? www mentions both! Even Ubu too)

Link about predictable network interface names: https://www.freedesktop.org/wiki/Sof...nterfaceNames/.

If you are talking about "bug", it is certainly not bug that eno1 exists as a name, but that second interface was not assigned "proper" name and changed name between reboots. If you do not like this feature of systemd, you can turn it off, at bottom of that page you have possible 3 methods for that.

1 members found this post helpful.

Hi thanks for reply. I notice that when i power up my server first time and put the command "ip a" it shows eth0 and eno1 and when i chech the /etc/sysconfig/network-scripts there are two files "eth1" and "eno1"

When i rboot the server then in ip a shows "eth1" "eno1"

Please check the logs:

ocalhost kernel: igb: Intel(R) Gigabit Ethernet Network Driver - version 5.3.0-k
localhost kernel: igb 0000:02:00.0: added PHC on eth0
localhost kernel: igb 0000:02:00.0: Intel(R) Gigabit Ethernet Network Connection
localhost kernel: igb 0000:02:00.0: eth0: (PCIe:2.5Gb/s:Width x1) 00:1e:67:a0:0c:8c
localhost kernel: igb 0000:02:00.0: eth0: PBA No: 102100-000
localhost kernel: igb 0000:03:00.0: added PHC on eth1
localhost kernel: igb 0000:03:00.0: Intel(R) Gigabit Ethernet Network Connection
localhost kernel: igb 0000:03:00.0: eth1: (PCIe:2.5Gb/s:Width x1) 00:1e:67:a0:0c:8d
localhost kernel: igb 0000:03:00.0: eth1: PBA No: 102100-000
localhost systemd-udevd: Error changing net interface name 'eth1' to 'eno1': File exists
localhost systemd-udevd: could not rename interface '3' from 'eth1' to 'eno1': File exists
localhost systemd-udevd: Error changing net interface name 'eth1' to 'eno1': File exists
localhost systemd-udevd: could not rename interface '3' from 'eth1' to 'eno1': File exists
localhost NetworkManager[740]: <info> [1502715453.7620] ifcfg-rh: new connection /etc/sysconfig/network-scripts/ifcfg-eth1 (52eea4ab-79f6-4c98-86db-93a1640422df,"eth1")
localhost NetworkManager[740]: <info> [1502715453.7620] ifcfg-rh: new connection /etc/sysconfig/network-scripts/ifcfg-eth1 (52eea4ab-79f6-4c98-86db-93a1640422df,"eth1")
localhost NetworkManager[740]: <info> [1502715453.8444] Loaded device plugin: NMVethFactory (internal)
localhost NetworkManager[740]: <info> [1502715453.8444] Loaded device plugin: NMEthernetFactory (internal)
localhost NetworkManager[740]: <info> [1502715453.8583] manager: (eno1): new Ethernet device (/org/freedesktop/NetworkManager/Devices/1)
localhost NetworkManager[740]: <info> [1502715453.9062] manager: (eth1): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
localhost NetworkManager[740]: <info> [1502715453.9062] manager: (eth1): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
localhost NetworkManager[740]: <info> [1502715453.9067] device (eth1): state change: unmanaged -> unavailable (reason 'managed') [10 20 2]

Hi thanks for reply. I notice that when i power up my server first time and put the command "ip a" it shows eth0 and eno1 and when i chech the /etc/sysconfig/network-scripts there are two files "eth1" and "eno1"

When i rboot the server then in ip a shows "eth1" "eno1"

Please check the logs:

ocalhost kernel: igb: Intel(R) Gigabit Ethernet Network Driver - version 5.3.0-k
localhost kernel: igb 0000:02:00.0: added PHC on eth0
localhost kernel: igb 0000:02:00.0: Intel(R) Gigabit Ethernet Network Connection
localhost kernel: igb 0000:02:00.0: eth0: (PCIe:2.5Gb/s:Width x1) 00:1e:67:a0:0c:8c
localhost kernel: igb 0000:02:00.0: eth0: PBA No: 102100-000
localhost kernel: igb 0000:03:00.0: added PHC on eth1
localhost kernel: igb 0000:03:00.0: Intel(R) Gigabit Ethernet Network Connection
localhost kernel: igb 0000:03:00.0: eth1: (PCIe:2.5Gb/s:Width x1) 00:1e:67:a0:0c:8d
localhost kernel: igb 0000:03:00.0: eth1: PBA No: 102100-000
localhost systemd-udevd: Error changing net interface name 'eth1' to 'eno1': File exists
localhost systemd-udevd: could not rename interface '3' from 'eth1' to 'eno1': File exists
localhost systemd-udevd: Error changing net interface name 'eth1' to 'eno1': File exists
localhost systemd-udevd: could not rename interface '3' from 'eth1' to 'eno1': File exists
localhost NetworkManager[740]: <info> [1502715453.7620] ifcfg-rh: new connection /etc/sysconfig/network-scripts/ifcfg-eth1 (52eea4ab-79f6-4c98-86db-93a1640422df,"eth1")
localhost NetworkManager[740]: <info> [1502715453.7620] ifcfg-rh: new connection /etc/sysconfig/network-scripts/ifcfg-eth1 (52eea4ab-79f6-4c98-86db-93a1640422df,"eth1")
localhost NetworkManager[740]: <info> [1502715453.8444] Loaded device plugin: NMVethFactory (internal)
localhost NetworkManager[740]: <info> [1502715453.8444] Loaded device plugin: NMEthernetFactory (internal)
localhost NetworkManager[740]: <info> [1502715453.8583] manager: (eno1): new Ethernet device (/org/freedesktop/NetworkManager/Devices/1)
localhost NetworkManager[740]: <info> [1502715453.9062] manager: (eth1): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
localhost NetworkManager[740]: <info> [1502715453.9062] manager: (eth1): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
localhost NetworkManager[740]: <info> [1502715453.9067] device (eth1): state change: unmanaged -> unavailable (reason 'managed') [10 20 2]

I'm not sure what I'm 'checking' your log for?

If you mean any lines, that show systemd is renaming your network interfaces, it's in bold.

I'm not trying to be rude but, others have provided some links to stop systemd renaming your network interfaces (posts #3 & #4).

Good luck with it!

Is one of those cards attached as USB device? There was some bug because systemd insisted on assigning predictable names based on mac address of device and it could not be done for USB devices, or something like that. Anyway, reverting to unpredictable names should solve your problem. Or/and, bug report it.

As per your reply I did

i add "net.ifnames=0" and "biosdevname=0" in "/etc/sysconfig/grub" and in line of "GRUB_CMDLINE_LINUX and reboot the server and still getting the error and now in "ip a" shows "eno1" and "eth0' and /etc/sysconfig/network-script have "ifcfg-eth1" and "ifcfg-eno1" find below the logs:

localhost kernel: igb: Intel(R) Gigabit Ethernet Network Driver - version 5.3.0-k
localhost kernel: igb 0000:02:00.0: added PHC on eth0
localhost kernel: igb 0000:02:00.0: Intel(R) Gigabit Ethernet Network Connection
localhost kernel: igb 0000:02:00.0: eth0: (PCIe:2.5Gb/s:Width x1) 00:1e:67:a0:0c:8c
localhost kernel: igb 0000:02:00.0: eth0: PBA No: 102100-000
localhost kernel: igb 0000:03:00.0: added PHC on eth1
localhost kernel: igb 0000:03:00.0: Intel(R) Gigabit Ethernet Network Connection
localhost kernel: igb 0000:03:00.0: eth1: (PCIe:2.5Gb/s:Width x1) 00:1e:67:a0:0c:8d
localhost kernel: igb 0000:03:00.0: eth1: PBA No: 102100-000
localhost systemd-udevd: Error changing net interface name 'eth0' to 'eno1': File exists
localhost systemd-udevd: could not rename interface '2' from 'eth0' to 'eno1': File exists
localhost systemd-udevd: Error changing net interface name 'eth0' to 'eno1': File exists
localhost systemd-udevd: could not rename interface '2' from 'eth0' to 'eno1': File exists
localhost NetworkManager[739]: <info> [1502723061.9225] ifcfg-rh: new connection /etc/sysconfig/network-scripts/ifcfg-eth1 (52eea4ab-79f6-4c98-86db-93a1640422df,"eth1")
localhost NetworkManager[739]: <info> [1502723061.9225] ifcfg-rh: new connection /etc/sysconfig/network-scripts/ifcfg-eth1 (52eea4ab-79f6-4c98-86db-93a1640422df,"eth1")
localhost NetworkManager[739]: <info> [1502723061.9985] Loaded device plugin: NMVethFactory (internal)
localhost NetworkManager[739]: <info> [1502723061.9986] Loaded device plugin: NMEthernetFactory (internal)
localhost NetworkManager[739]: <info> [1502723062.0122] manager: (eth0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/1)
localhost NetworkManager[739]: <info> [1502723062.0122] manager: (eth0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/1)
localhost NetworkManager[739]: <info> [1502723062.0132] settings: (eth0): created default wired connection 'Wired connection 1'
localhost NetworkManager[739]: <info> [1502723062.0138] device (eth0): state change: unmanaged -> unavailable (reason 'managed') [10 20 2]

The LAN cards are onboard NIC and it is a inter Server Board.

i add "net.ifnames=0" and "biosdevname=0" in "/etc/sysconfig/grub" and in line of "GRUB_CMDLINE_LINUX and reboot the server and still getting the error and now in "ip a" shows "eno1" and "eth0' and /etc/sysconfig/network-script have "ifcfg-eth1" and "ifcfg-eno1" find below the logs:


localhost kernel: igb: Intel(R) Gigabit Ethernet Network Driver - version 5.3.0-k
localhost kernel: igb 0000:02:00.0: added PHC on eth0
localhost kernel: igb 0000:02:00.0: Intel(R) Gigabit Ethernet Network Connection
localhost kernel: igb 0000:02:00.0: eth0: (PCIe:2.5Gb/s:Width x1) 00:1e:67:a0:0c:8c
localhost kernel: igb 0000:02:00.0: eth0: PBA No: 102100-000
localhost kernel: igb 0000:03:00.0: added PHC on eth1
localhost kernel: igb 0000:03:00.0: Intel(R) Gigabit Ethernet Network Connection
localhost kernel: igb 0000:03:00.0: eth1: (PCIe:2.5Gb/s:Width x1) 00:1e:67:a0:0c:8d
localhost kernel: igb 0000:03:00.0: eth1: PBA No: 102100-000
localhost systemd-udevd: Error changing net interface name 'eth0' to 'eno1': File exists
localhost systemd-udevd: could not rename interface '2' from 'eth0' to 'eno1': File exists
localhost systemd-udevd: Error changing net interface name 'eth0' to 'eno1': File exists
localhost systemd-udevd: could not rename interface '2' from 'eth0' to 'eno1': File exists
localhost NetworkManager[739]: <info> [1502723061.9225] ifcfg-rh: new connection /etc/sysconfig/network-scripts/ifcfg-eth1 (52eea4ab-79f6-4c98-86db-93a1640422df,"eth1")
localhost NetworkManager[739]: <info> [1502723061.9225] ifcfg-rh: new connection /etc/sysconfig/network-scripts/ifcfg-eth1 (52eea4ab-79f6-4c98-86db-93a1640422df,"eth1")
localhost NetworkManager[739]: <info> [1502723061.9985] Loaded device plugin: NMVethFactory (internal)
localhost NetworkManager[739]: <info> [1502723061.9986] Loaded device plugin: NMEthernetFactory (internal)
localhost NetworkManager[739]: <info> [1502723062.0122] manager: (eth0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/1)
localhost NetworkManager[739]: <info> [1502723062.0122] manager: (eth0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/1)
localhost NetworkManager[739]: <info> [1502723062.0132] settings: (eth0): created default wired connection 'Wired connection 1'
localhost NetworkManager[739]: <info> [1502723062.0138] device (eth0): state change: unmanaged -> unavailable (reason 'managed') [10 20 2]

Well, systemd is supposed to ensure that network interface names don't change across reboots. If that is what is occurring, then it's working. I don't quite understand what the problem is. Is it that you want "eth0" and "eth1" as interface names? Because systemd doesn't always use those anymore.

I would check out the link posted by: dejank in #4.