I had set up a vlan in interfaces file. Later on, even after removing the entries and restarting network, the ifconfig command is displaying that interface. Even ifdown isnt taking it down. Ifdown throws error message that the interface isnt configured.
Even after multiple times of examination, I am seeing the same thing again. Wondering why it worked in the same way in the Oracle VM Virtual Box also. Even after commenting-out in the interfaces file, networking restart, networking stop / start, ifdown && ifup, even machine reboot also..!! Same experience..!! Could somebody please try this and explain..?
23 Answers
I had this problem while I used Netplan to add a VLAN on Ubuntu 18.04 Bionic. It did no go away when I removed it from the Yaml file. I even wan't able to create a new VLAN with the same VLAN ID because the previous one was not removed.
I solved this using this command:
ip link delete name [VLAN-NAME]Edit /etc/network/interfaces
sudo gedit /etc/network/interfacesRemove the vlan entries
Now you have to restart the interface
sudo ifdown eth0 you can ignore the error if it appears here then
sudo ifup etho Now check again ifconfig
If it still shows that entry you may need to make a system reboot.
11If anybody comes across this now, I hope this helps!
Unfortunately, in order to get the interface to go away, you will need to re-create a valid config; this could be as simple as
DEVICE=eth2.508
BOOTPROTO=none
VLAN=yesBring up the interface with
ifup eth2.508If successful, you can then bring the interface back down
ifdown eth2.508At this point, you should see the interface removed from ifconfig, and can safely move the config file from your network scripts folder.
The lesson to be learned from this is to bring down an interface before deleting it!
I also strongly recommend moving the configs to an archive directory instead of deleting them in case a situation arises that it becomes required/desired again. On my CentOS servers, I would do
cd /etc/sysconfig/network-scripts
mkdir if-archive
mv ./eth2.508 ./if-archive/eth2.508.20170621-01You'll notice the filename has yyyymmdd-vv appended to it; the -vv is for if you have multiple configs from the same date, you can manually increment this to keep multiple copies. If you don't have a need, don't add it.
