Technologie NAT traversal

Abstract

Nowadays, in connection with the growth of the Internet, there is also a shortage of public IP addresses, which are used as unique identifiers of the devices in a computer network. For this reason, an effort has been initiated to address this problem. One possible solution is the use of network address translation, known as NAT. With the developing Internet and modern computer networks, demand for secure interconnection of individual networks and secure connection for the remote users raised. For this purpose, VPN technology can be used. The theoretical part of this thesis, therefore, deals with NAT, VPN technology and mechanisms that deal with problems caused by NAT. The practical part of the thesis aims to the configuration of the VPN technologies in a network that uses NAT. VPN technologies which are negatively affected by network address translation has been intentionally chosen so it is necessary to apply the methods solving the arisen problems. Tested topologies are composed of Cisco and Huawei routers. Therefore, also compatibility between the devices of both manufacturers has been tested to enable their easy usage in practice.