The purpose of this thesis is to describe in detail the configuration of an IPSec VPN tunnel using a "MikroTik" router. Internet Protocol Security (IPSec) is a secure network protocol suite that authenticates and encrypts the packets of data to provide secure encrypted communication between two computers over an Internet Protocol network. IPsec may be used in three different security domains: virtual private networks, application-level security and routing security. At this time, IPsec is predominately used in VPNs. "MikroTik" is a Latvian network equipment company founded in 1996, which develops and sells wired and wireless network routers, network switches, access points, software and hardware, antennas and more other products. We performed the entire configuration of the thesis in the "Winbox" program. It is a program that allows easy access to "MikroTik" settings, while using a graphical interface. This thesis can be divided into two parts. The first part refers to the general part of theoretical knowledge about IPSec and VPN, technical characteristics of the devices used, basic steps for access the configuration and settings of the computer which we use to access the "Winbox" program or router. The second part refers to the practical part which shows schematic presentation of the project. All the steps required for the configuration of the IPSec tunnel will be presented pictorially and detailed.