31 Days Before Your CCNA Exam

322 31 Days Before Your CCNA ExamVPN ComponentsFigure 4-14 illustrates a typical VPN topology. Components required to establish this VPN includethe following:■■■■An existing enterprise network with servers and workstationsA connection to the InternetVPN gateways, such as routers, firewalls, VPN concentrators, and ASAs, that act as endpointsto establish, manage, and control VPN connectionsAppropriate software to create and manage VPN tunnelsFigure 4-14VPN ComponentsEnterprise orCorporate NetworkBusiness Partner with RouterFirewallVPNConcentratorInternetRemote Office with RouterPerimeterRouterPOPRegional Office with FirewallSOHO with BroadbandConnectionTeleworker with VPNClient on LaptopComputerEstablishing Secure VPN ConnectionsVPNs secure data by encapsulating and encrypting it. With regard to VPNs, encapsulation andencryption are defined as follows:■■Encapsulation is also called tunneling, because encapsulation transmits data transparentlyfrom source network to destination network through a shared network infrastructure.Encryption codes data into a different format using a secret key, which is then used on theother side on the connection to decrypt.