Cisco VPN 3000 LAN-to-LAN Networks Review

This chapter looked at using Cisco VPN 3000 Series Concentrator devices in LAN-to- LAN VPN implementations. The VPN Concentrator works as an endpoint device in these implementations. While the peer device can be a router, PIX firewall, Cisco VPN 3002 hardware client, or third-party VPN device, this chapter and the features that will be tested on the exam assume Cisco VPN Concentrators will be on both ends of the link.

LAN-to-LAN (site-to-site) VPNs are a rapidly expanding alternative or augmentation to leased line or Frame Relay WAN infrastructures. VPNs are used to create secure tunnels between two networks via an insecure public network, such as the Internet. The Cisco Concentrator supports three types of tunnels: Layer 2 Tunneling Protocol (L2TP), Point-to-Point Tunneling Protocol (PPTP), and IPSec.

Two types of LAN-to-LAN VPN implementations exist.

• Intranet VPNs provide secure connections between branch offices to the enterprise network resources.

• Extranet VPNs provide secure connections for special third parties, such as business partners, vendors, and customers to the specified enterprise resources.

The Concentrator menu-driven system is used to configure basic LAN-to-LAN VPN parameters, as well as to enable and define features like NAT Transparency and VPN routing features, such as reverse route injection (RRI) and Virtual Router Redundancy Protocol (VRRP).