building linux virtual private networks vpns pdf

... VPNs February 2006 [11] Fang, L., "Security Framework for Provider-Provisioned Virtual Private Networks (PPVPNs)", RFC 4111, July 2005. [12] Behringer, M., Guichard, J., and P. Marques, ... Inc Category: Informational February 2006 Analysis of the Security of BGP/MPLS IP Virtual Private Networks (VPNs) Status of This Memo This memo provides information for the Internet community. ... support. 10. Normative References [1] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private Networks (VPNs) ", RFC 4364, February 2006. 11. Informative References [2] Rekhter, Y.,...

... cho các học viên lớp MCSA - www.athenavn.com Cách thiết lập VPN (Virtual Private Networks) Client - Phần II Virtual Private Networks (VPN) hay gọi theo tiếng Việt là Mạng Riêng Ảo, cho phép ... Properties, double click vào Make New Connection, sau đó click Next 2. Chọn vào Connect to private network through the Internet theo hình dưới đây. 3. Nếu bạn chưa kết nối với internet...

... Cisco IOS command syntax uses the more specific term virtual private dialup network (VPDN) instead of VPN. Enables VPN. Configuring Virtual Private Networks Verifying VPN Sessions DNC-176 Cisco IOS ... Configuration Guide: Network Services Configuring Virtual Private Networks This chapter describes how to configure, verify, maintain, and troubleshoot a Virtual Private Network (VPN). It includes the following ... AAA Negotiation Configuring Virtual Private Networks Prerequisites for VPNs DNC-160 Cisco IOS Dial Services Configuration Guide: Network Services Prerequisites for VPNs Before configuring a VPN,...

... solution to this problem is Virtual Private Networks (VPNs) . VPNs are a cost effective way to− extend your LAN over the Internet to remote networks and remote client computers. VPNs use the Internet ... most modern VPN systems are combined with firewalls in a single device. Virtual Private Networking Explained Virtual Private Networks solve the problem of direct Internet access to servers through ... these services. There are three types of VPNs: • Server based VPNs • Firewall based VPNs • Router based VPNs including VPN appliances− Server−Based VPNs In a Windows based network, perhaps...

... etc.). Overview 44 Figure 2-2 IKE Phase II Once the IPSec keys are created, bulk data transfer takes place: Virtual Private Networks Administration Guide Version NGX R65 701675 March 18, 2007 Table of Contents 5 Contents Preface ... Period 81 Configuring OCSP 82 Chapter 4 Introduction to Site to Site VPN The Need for Virtual Private Networks 84 Confidentiality 84 Authentication 84 Integrity 84 The Check Point Solution for ... and server requirements. Integrity Agent for Linux Installation and Configuration Guide Explains how to install and configure Integrity Agent for Linux. Integrity XML Policy Reference Guide Provides...

... • mesh of hubs • star of hubs Virtual Private Networks (VPNs) • Used to connect two private networks together via the Internet • Used to connect remote users to a private network via the Internet • This ... work together • make sure that remote clients software works with your firewall VPN • Virtual Private Networks CS-480b Dick Steflik ... a VPN in conjunction with your firewall Types of VPNs • Server based • Firewall based • Router based (including VPN appliances IP Based VPNs • Fundamental Components • IP Encapsulation • Cryptographic...

... vì nó không đòi hỏi certificate hay là PKI (Public Key Infrastructure) như L2TP. Virtual Private Networks (VPN) hay gọi theo tiếng Việt là Mạng Riêng Ảo, cho phép bạn mở rộng phạm vi mạng ... dial the initial connection theo hình dưới đây và Click Next Cách thiết lập VPN (Virtual Private Networks) Client ... Properties, double click vào Make New Connection, sau đó click Next 2. Chọn vào Connect to private network through the Internet theo hình dưới đây. 3. Nếu bạn chưa kết nối với internet...

... 4.4 Structure of Linux 4.5 The Linux development model maximizes learning 4.6 Positive Network Effects driving ongoing growth-adoption of the GNU /Linux operating system 6.1 Linux structure ... Linux is gaining critical mass Linux becomes more -powerful -portable -features/applications are added Linux developers add features, identify bugs, port it to other platforms Linux ... instead of radical 48 CHAPTER 5: MICROSOFT Vs. LINUX Table 5.1: Microsoft Vs. Linux Project MICROSOFT (PHYSICAL) LINUX PROJECT (VIRTUAL) Business Processes (development) Cost...

... employed at Verismo Networks, India, he is part of the embedded Linux team responsible for media solutions. Contents xiii 7 Real-Time Linux 201 7.1 Real-Time Operating System 202 7.2 Linux and Real-Time ... applications from standard Linux to uClinux. It also explains how to build applications for uClinux. Appendix A, “Booting Faster,” explains various techniques to reduce Linux boot-up time. Appendix ... Linux Guide (DULG). It is an extensive document regarding Ⅲ Installation and building ELDK components Ⅲ Target image configuration, RFS building, and downloading onto the target Ⅲ U-boot and Linux...

... SUMMARY  VPNs do not make use of dedicated  leased lines  VPNs send data through a secure tunnel  that leads from one endpoint to another   VPNs keep critical business  communications private and secure  VPN components  VPN servers  VPN clients  Protocols 39 TUNNELING PROTOCOLS  Layer 2 Tunneling Protocol (L2TP)  Provides better security through IPSec  IPSec enables L2TP to perform  Authentication  Encapsulation  Encryption 18 TUNNELING PROTOCOLS  Secure Shell (SSH)  Provides authentication and encryption  Works with UNIX­based systems  Versions for Windows are also available  Uses public­key cryptography  Socks V. 5  Provides proxy services for applications   That do not usually support proxying  Socks version 5 adds encrypted authentication and  support for UDP 20 16 ENCRYPTION SCHEMES USED BY  VPNS (CONTINUED)  Secure Sockets Layer (SSL) (continued)  Steps  Server uses its private key to decode pre­master code  Generates a master secret key  Client and server use it to generate session keys  Server and client exchange messages saying handshake is  completed  SSL session begins 34 SUMMARY (CONTINUED)  VPN types  Site­to­site  Client­to­site  Encapsulation encloses one packet within  another   Conceals the original information  VPN protocols  Secure Shell (SSH)  Socks version 5  Point­to­Point Tunneling Protocol (PPTP)  Layer 2 Tunneling Protocol (L2TP) 40 Virtual Private Network  (VPN)  29 BIếN ĐổI ĐÓNG GÓI TRONG VPN  (ENCAPSULATION)  Các buớc trong tiến trình VPN   Đóng gói (Encapsulation)  Mã hoá (Encryption)  Xác thực (Authentication)  Encapsulation  Đóng gói dữ liệu và các thông số khác nhau  Ví dụ như IP header  Bảo vệ tính nguyên vẹn dữ liệu 15 31 27 VPN CORE ACTIVITY 2: ENCRYPTION  Encryption  Process of rendering information unreadable  by all but the intended recipient  Components  Key  Digital certificate  Certification Authority (CA)  Key exchange methods  Symmetric cryptography  Asymmetric cryptography  Internet Key Exchange  FWZ 28 12 SUMMARY (CONTINUED)  IPSec/IKE  Encryption makes the contents of the  packet unreadable  Authentication ensures participating  computers are authorized users  Kerberos: strong authentication system  VPN advantages  High level of security at low cost  VPN disadvantages  Can introduce serious security risks 41 24 10 25 5 ENCRYPTION SCHEMES USED BY  VPNS  Triple Data Encryption Standard (3DES)  Used by many VPN hardware and software  3DES is a variation on Data Encryption Standard  (DES)  DES is not secure  3DES is more secure  Three separate 64­bit keys to process data  3DES requires more computer resources than DES 30 WHY ESTABLISH A VPN?  VPN combinations  Combining VPN hardware with software adds  layers of network security  One useful combination is a VPN bundled with a  firewall  VPNs do not eliminate the need for firewalls  Provide flexibility and versatility 13 FIREWALL CONFIGURATION FOR  VPNS 37 Protocol ... 1723 TUNNELING PROTOCOLS  Point­to­Point Tunneling Protocol (PPTP)  Used when you need to dial in to a server with  a modem connection  On a computer using an older OS version  Encapsulates TCP/IP packets  Header contains only information needed to  route data from the VPN client to the server  Uses Microsoft Point­to­Point Encryption  (MPPE)  Encrypt data that passes between the remote computer  and the remote access server  L2TP uses IPSec encryption  More secure and widely supported 17 NỘI DUNG  Nguyên lý VPN  Các biến đổi đóng gói trong VPNs  Mã hoá trong VPNs  Xác thực trong VPNs  Ưu nhược điểm của VPNs 2 VPN CORE ACTIVITY 3:  AUTHENTICATION  Authentication  Identifying a user or computer as authorized to  access and use network resources  Types of authentication methods used in VPNs  IPSec  MS­CHAP  Both computers exchange authentication packets and  authenticate one another  VPNs use digital certificates to authenticate users 35 ... SUMMARY  VPNs do not make use of dedicated  leased lines  VPNs send data through a secure tunnel  that leads from one endpoint to another   VPNs keep critical business  communications private and secure  VPN components  VPN servers  VPN clients  Protocols 39 TUNNELING PROTOCOLS  Layer 2 Tunneling Protocol (L2TP)  Provides better security through IPSec  IPSec enables L2TP to perform  Authentication  Encapsulation  Encryption 18 TUNNELING PROTOCOLS  Secure Shell (SSH)  Provides authentication and encryption  Works with UNIX­based systems  Versions for Windows are also available  Uses public­key cryptography  Socks V. 5  Provides proxy services for applications   That do not usually support proxying  Socks version 5 adds encrypted authentication and  support for UDP 20 16 ENCRYPTION SCHEMES USED BY  VPNS (CONTINUED)  Secure Sockets Layer (SSL) (continued)  Steps  Server uses its private key to decode pre­master code  Generates a master secret key  Client and server use it to generate session keys  Server and client exchange messages saying handshake is  completed  SSL session begins 34 SUMMARY (CONTINUED)  VPN types  Site­to­site  Client­to­site  Encapsulation encloses one packet within  another   Conceals the original information  VPN protocols  Secure Shell (SSH)  Socks version 5  Point­to­Point Tunneling Protocol (PPTP)  Layer 2 Tunneling Protocol (L2TP) 40 Virtual Private Network  (VPN)  29 BIếN ĐổI ĐÓNG GÓI TRONG VPN  (ENCAPSULATION)  Các buớc trong tiến trình VPN   Đóng gói (Encapsulation)  Mã hoá (Encryption)  Xác thực (Authentication)  Encapsulation  Đóng gói dữ liệu và các thông số khác nhau  Ví dụ như IP header  Bảo vệ tính nguyên vẹn dữ liệu 15 31 27 VPN CORE ACTIVITY 2: ENCRYPTION  Encryption  Process of rendering information unreadable  by all but the intended recipient  Components  Key  Digital certificate  Certification Authority (CA)  Key exchange methods  Symmetric cryptography  Asymmetric cryptography  Internet Key Exchange  FWZ 28 12 SUMMARY (CONTINUED)  IPSec/IKE  Encryption makes the contents of the  packet unreadable  Authentication ensures participating  computers are authorized users  Kerberos: strong authentication system  VPN advantages  High level of security at low cost  VPN disadvantages  Can introduce serious security risks 41 24 10 25 5 ENCRYPTION SCHEMES USED BY  VPNS  Triple Data Encryption Standard (3DES)  Used by many VPN hardware and software  3DES is a variation on Data Encryption Standard  (DES)  DES is not secure  3DES is more secure  Three separate 64­bit keys to process data  3DES requires more computer resources than DES 30 WHY ESTABLISH A VPN?  VPN combinations  Combining VPN hardware with software adds  layers of network security  One useful combination is a VPN bundled with a  firewall  VPNs do not eliminate the need for firewalls  Provide flexibility and versatility 13 FIREWALL CONFIGURATION FOR  VPNS 37 Protocol...