cisco ccna for dummies pdf

cisco ccna for dummies pdf.. Site-to-site VPNs.. Remote Access VPNO The next few subsections cover them in more depth.Site-to-Site VPNA site-to-site VPN, sometimes referred to as a LAN.to.LAN or L2LVPN, connects two sites and is an extension of the traditional WAN design. Two intermediate devices, often called VPN gateways, are responsible for protecting the traffic that travels between the two LANs. This VPN transmits packets between the two sites through a tunnel: the VPN gateway encrypts the IP packets from the LAN and forwards them to the destination gateway; the destination gateway decrypts the IP packets and forwards them to the destination device. To the source and target devices, the VPN is virtual-they have no idea that their traffic is being protected as it travels between the two VPN gateways. IPSec is the site-to-site protocol most commonly used to protect traffic. VPN gateway devices are usually routers, but they can also be other devices such as firewalls. Cisco products that support IPSecL2LVPN include routers and ASA security appliances; Cisco routers offer scalability features such as Dynamic Multipoint VPN (DMVPN) and are better suited than ASA security appliances for use as IPSec L2L gateways.There are two types of L2Ls: Intranet and Extranet. Intranet L2Ls connect two sites of the same company, such as a headquarters and a regional office or branch office; extranet L2LVPNs connect two companies, such as a headquarters and a business partner, and often require address translation because both companies may use the same private address space.Remote access VPNs are extensions to traditional circuit-switched networks, such as POTS and ISDN, to securely connect remote users or SOHOs to a headquarters or branch office. Remote access VPNs provide virtualized processing, allowing remote access users or branch offices to act as if they had a physical connection to the headquarters network. Common protocols used for remote access VPNs include IPSec, SSL, PPTP, and L2TP. Cisco supports all four protocols, but has focused its primary development efforts on IPSec and SSL, which are discussed in the next two subsections.Easy VPNCisco's IPSec remote access solution is called EasyVPN, where Easy refers to Cisco's design approach that makes the solution easy to deploy and supports centralized configuration of a large number of users and policies. EasyVPN consists of two components.. Easy VPN server.. Easy VPN Remote (client).