华为培训课程MPLS-VPN.ppt

利用公共网络来构建的私有专用网络称为虚拟私有网络(VPN,Virtual Private Network)。物理上所有VPN接入在同一张公共网络中,逻辑上每个VPN是一张独立的网络。 构建在这些公共网络上的VPN将象当前企业私有的网络一样提供安全性、可靠性和可管理性等。保持了各自的独立性和私密性。 企业可以用明显更低的成本连接它们的远地办事机构、出差工作人员以及业务合作伙伴。运营商在一个网络上提供了多种业务，提高了设备和链路的利用率，节省了成本，拓展了新的业务。 VPN的实现可以通过M P L S、虚拟路由器和隧道等技术实现 VPN分类 按接入方式 □专线VPN －用户通过专线（包括VLAN）接入ISP边缘路由器,如VPRN、 VPLS、VLL。 □拨号VPN －又称VPDN，用户利用拨号方式接入ISP。 按隧道协议层次 □第二层隧道协议－如PPTP、L2F、L2TP、MPLS、UTI。 □第三层隧道协议－如GRE和IPSec。 按VPN的工作模式 □叠加模式（网络基础和用户网络工作在不同层次） －如GRE和IPSec □对等模式（网络基础和用户网络工作在同一层次） －如MPLS MPLS-VPN的相关概念 IGP—Interior Gateway Protocol. An Internet protocol used to exchange routing information within an autonomous system. Examples of common IBGPs include IGRP, OSPF, and RIP. BGP—Border Gateway Protocol. Interdomain routing protocol that exchanges reachability information with other BGP systems. It is defined in RFC 1163. Provider Network (P-Network)--The backbone under control of a Service Provider Customer Network (C-Network)--Network under customer control CE router—Customer edge router. A router that is part of a customer network and that interfaces to a provider edge (PE) router. CE routers are not aware of associated VPNs. PE router—Provider edge router. A router that is part of a service provider’s network connected to a customer edge (CE) router. All VPN processing occurs in the PE router. LSR—Label-switched router MPLS—Multiprotocol Label Switching. An emerging industry standard. LDP--Label Distribution Protocol MPLS-VPN的相关概念 VPN—Virtual private network. A secure IP-based network that shares resources on one or more physical networks. A VPN contains geographically dispersed sites that can communicate securely over a shared backbone. vpnv4—Used as a keyword in commands to indicate VPN-IPv4 prefixes. These prefixes are customer VPN addresses, each of which has been made unique by the addition of an 8-byte route distinguisher. VRF—VPN routing/forwardin