Friday, February 3, 2012 - 13:54
Many corporate networks are shielded from the outside world by firewall devices or by the simple expedient of running the network on private IP addresses that are not routed over the global Internet. Either or both of these measures may be present at both ends of a VPN, preventing external packets from reaching systems connected to the LAN. However the purpose of a VPN is to allow a remote host or site to become part of the LAN, and so the security measures used to guard against intrusion from the Internet must be selectively circumvented to allow the VPN to work.
