RFC 2764 IP Based Virtual Private Networks February 2000 Table of Contents 1.0 Introduction ................................................ 4 2.0 VPN Application and Implementation Requirements ............. 5 2.1 General VPN Requirements .................................... 5 2.1.1 Opaque Packet Transport: ................................. 6 2.1.2 Data Security ............................................. 7 2.1.3 Quality of Service Guarantees ............................. 7 2.1.4 Tunneling Mechanism ....................................... 8 2.2 CPE and Network Based VPNs .................................. 8 2.3 VPNs and Extranets .......................................... 9 3.0 VPN Tunneling ............................................... 10 3.1 Tunneling Protocol Requirements for VPNs .................... 11 3.1.1 Multiplexing .............................................. 11 3.1.2 Signalling Protocol ....................................... 12 3.1.3 Data Security ............................................. 13 3.1.4 Multiprotocol Transport ................................... 14 3.1.5 Frame Sequencing .......................................... 14 3.1.6 Tunnel Maintenance ........................................ 15 3.1.7 Large MTUs ................................................ 16 3.1.8 Minimization of Tunnel Overhead ........................... 16 3.1.9 Flow and congestion control ............................... 17 3.1.10 QoS / Traffic Management ................................. 17 3.2 Recommendations ............................................. 18 4.0 VPN Types: Virtual Leased Lines ............................ 18 5.0 VPN Types: Virtual Private Routed Networks ................. 20 5.1 VPRN Characteristics ........................................ 20 5.1.1 Topology .................................................. 23 5.1.2 Addressing ................................................ 24 5.1.3 Forwarding ................................................ 24 5.1.4 Multiple concurrent VPRN connectivity ..................... 24 5.2 VPRN Related Work ........................................... 24 5.3 VPRN Generic Requirements ................................... 25 5.3.1 VPN Identifier ............................................ 26 5.3.2 VPN Membership Information Configuration .................. 27 5.3.2.1 Directory Lookup ........................................ 27 5.3.2.2 Explicit Management Configuration ....................... 28 5.3.2.3 Piggybacking in Routing Protocols ....................... 28 5.3.3 Stub Link Reachability Information ........................ 30 5.3.3.1 Stub Link Connectivity Scenarios ........................ 30 5.3.3.1.1 Dual VPRN and Internet Connectivity ................... 30 5.3.3.1.2 VPRN Connectivity Only ................................ 30 5.3.3.1.3 Multihomed Connectivity ............................... 31 5.3.3.1.4 Backdoor Links ........................................ 31 5.3.3.1 Routing Protocol Instance ............................... 31 5.3.3.2 Configuration ........................................... 33 5.3.3.3 ISP Administered Addresses .............................. 33 5.3.3.4 MPLS Label Distribution Protocol ........................ 33 Gleeson, et al. Informational