ipsec-tools software package provides IPsec utilities, 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 ipsec-tools
ipsec-tools is installed in your system.
Make ensure the ipsec-tools package were installed using the commands given below,
$ sudo dpkg-query -l | grep ipsec-tools *
You will get with ipsec-tools package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Network |
| Package | ipsec-tools |
| Version | 1:0.8.2+20140711-5 |
| Description | IPsec utilities |
| Sub Section | Net |