ifupdown-extra software package provides Network scripts for ifupdown, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install ifupdown-extra
ifupdown-extra is installed in your system.
Make ensure the ifupdown-extra package were installed using the commands given below,
$ sudo dpkg-query -l | grep ifupdown-extra *
You will get with ifupdown-extra package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Administration Utilities |
| Package | ifupdown-extra |
| Version | 0.26 |
| Description | Network scripts for ifupdown |
| Sub Section | admin |