Remove network interface permanently

I'm trying to remove a network interface permanently. For some reason, ifconfig lists eth0 and eth1, although the latter RX/TX metrics remain at zero.

I suspect that extra eth1 entry might be causing delays during boot.

Surprinsgly, a search did not yield any answer on how to proceed. Most posts either are for older versions of Ubuntu or Debian, or for other distros (RedHat), or have no permanent effect, or pertain to adding an interface, or try to turn it off but after it's been started, or are simply unanswered. But the answer might be somewhere after Google's thrid result page.

Removing the second entry from the desktop (up and down arrows, on the top bar) has no effect either on ifconfig.

EDIT: I actutally do have two network cards on the MB. That's a bit of a surprise I admit. I don't have wifi. Question still stands, a least out of curiosity.

krakoukass@durum:~$ ifconfig
eth0 Link encap:Ethernet HWaddr 00:1f:d0:a3:40:d9 inet addr:192.168.1.66 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::21f:d0ff:fea3:40d9/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:84 errors:0 dropped:0 overruns:0 frame:0 TX packets:93 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:12255 (12.2 KB) TX bytes:12241 (12.2 KB)
eth1 Link encap:Ethernet HWaddr 00:1f:d0:a3:40:db UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:634 errors:0 dropped:0 overruns:0 frame:0 TX packets:634 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:64758 (64.7 KB) TX bytes:64758 (64.7 KB)
krakoukass@durum:~$ lspci | grep -i eth
04:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 02)
05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 02)
krakoukass@durum:~$ cat /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
krakoukas@durum:~$ systemctl -l status
● - ifup for eth1 Loaded: loaded (/lib/systemd/system/ifup@.service; static; vendor preset: enabled) Active: active (exited) since Fri 2015-05-15 12:36:34 CEST; 14min ago Process: 457 ExecStart=/bin/sh -ec ifup --allow=hotplug %I; ifup --allow=auto %I; if ifquery %I >/dev/null; then ifquery --state %I >/dev/null; fi (code=exited, status=0/SUCCESS) Main PID: 457 (code=exited, status=0/SUCCESS)
May 15 12:36:34 durum systemd[1]: Started ifup for eth1.
May 15 12:36:34 durum systemd[1]: Starting ifup for eth1...
May 15 12:36:34 durum sh[457]: Unknown interface eth1
krakoukas@durum:~$ systemctl -l status
● - ifup for eth0 Loaded: loaded (/lib/systemd/system/ifup@.service; static; vendor preset: enabled) Active: active (exited) since Fri 2015-05-15 12:36:34 CEST; 15min ago Process: 458 ExecStart=/bin/sh -ec ifup --allow=hotplug %I; ifup --allow=auto %I; if ifquery %I >/dev/null; then ifquery --state %I >/dev/null; fi (code=exited, status=0/SUCCESS) Main PID: 458 (code=exited, status=0/SUCCESS)
May 15 12:36:34 durum systemd[1]: Started ifup for eth0.
May 15 12:36:34 durum systemd[1]: Starting ifup for eth0...
May 15 12:36:34 durum sh[458]: Unknown interface eth0

Thanks in advance for you help.

2 Answers

Open the file /etc/network/interfaces in your terminal

sudo nano /etc/network/interfaces

Add this line:

iface eth1 inet manual

Save the file and run

sudo service network-manager restart

or

sudo systemctl restart network-manager.service

_Source

To remove permanently I think you should use this

sudo nmcli connection show

The result looks like:

NAME UUID TYPE DEVICE
front 2cf067c7-e0ad-4072-b60f-60a7733b5c27 wifi wlp1s0
wg0 ab0b9039-c4b1-48af-b30c-adcbea993643 wireguard wg0
WebSolutions 07749022-afa7-467e-a625-a87de9875ab7 vpn --
BlackHome 061a7dbf-5d7d-4992-a78d-015b3d93f5af wifi -- 

then remove by UUID

sudo nmcli connection delete ab0b9039-c4b1-48af-b30c-adcbea993643