Persistant changes in network configurations

hi Team ,

I must say this is an amazing course.Just trying to bring my doubts to table to understand whether there is any mistake in my side in understanding.

In networking module almost at the end of the module the instructor says if you want to make the networking changes persistant ( i.e. you don’t want to loose the configurations done by ip add , ip route etc ) you need to save those to /etc/network/interfaces file.

I logged into the lab which follows this module in order to check this file but unable to locate it .
I am in need to see this file and to understand how to make entries in this file so that after restart I wont loose any of these added new network configurations.

Is it possible for you to review and let me know what is missing here ?

bob@caleston-lp10:~ pwd/home/bob bob@caleston-lp10:~
bob@caleston-lp10:~ cd /etc/network bob@caleston-lp10:/etc/network ls
bob@caleston-lp10:/etc/network$ ls
bob@caleston-lp10:/etc/network$ cd …
bob@caleston-lp10:/etc$ pwd
bob@caleston-lp10:/etc$bob@caleston-lp10:/etc$ ls
X11 hostname modules resolv.confadduser.conf hosts modules-load.d rmt
alternatives hosts.allow mtab rpc
apparmor.d hosts.deny netconfig securetty
apt idmapd.conf network security
bash.bashrc init networkd-dispatcher selinux
bash_completion.d init.d networks services
bindresvport.blacklist inputrc nsswitch.conf shadow
binfmt.d insserv.conf.d opt shadow-
ca-certificates iproute2 os-release shells
ca-certificates.conf issue pam.conf skel
calendar pam.d ssh
cron.daily kernel passwd ssl
cron.weekly passwd- subgid
dbus-1 perl subgid-
debconf.conf profile subuid
debian_version ldap profile.d subuid-
default legal protocols sudoers
deluser.conf libaudit.conf python sudoers.d
depmod.d logcheck python2.7 sysctl.conf
dhcp login.defs python3 sysctl.d
dpkg logrotate.d python3.6 systemd
environment lsb-release rc0.d terminfo
fstab machine-id rc1.d tmpfiles.d
gai.conf magic rc2.d ucf.conf
groff magic.mime rc3.d udev
group mailcap rc4.d ufw
group- mailcap.order rc5.d update-motd.d
gshadow manpath.config rc6.d vim
gshadow- mime.types rcS.d wgetrc
gss mke2fs.conf request-key.conf xdg
host.conf modprobe.d request-key.d

bob@caleston-lp10:/etc$ cat /etc/network/interfaces
cat: /etc/network/interfaces: No such file or directory
bob@caleston-lp10:/etc$ cat /etc/networks/interfaces
cat: /etc/networks/interfaces: Not a directory

with best regards
Pradeep Nehe
Email :

Hi Pradeep,

Thanks for your feedback about the course!

You are correct - The interfaces file is not available in this case as it uses a minimalistic Ubuntu 18.04 in the lab. This is another reason why in the labs we have not asked he network configuration to be made persistent.

I will check if for this lab I can make an exception.