virtual private network remote access

... 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 ... 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 ...

... chia ra làm 2 phân loại chính sau :  Remote Access VPNs ( VPN truy cập từ xa).  Site – to – site VPNs (VPN điểm nối điểm). 3 Central Site Site-to-Site Remote Office Extranet Business Partner POP DSL Cable Mobile ... - In LuËn v¨n, TiÓu luËn  : 6.280.688 Lý thuyết.  I. Tổng quan về mạng riêng ảo VPN (Virtual Private Network) .  II. VPN và bảo mật internet VPN.  III. Thiết kế VPN I. Tổng quan về mạng riêng ... tiết kiệm được chi phí và thời gian. VPN ra đời đáp ứng tất cả các yêu cầu trên Cụm từ Virtual Private Network gọi là mạng riêng ảo- VPN được khởi sự năm 1997. Mục đích mong muốn của công nghệ...

... hiện nay là VPN truy cập từ xa (Remote- Access ) và VPN điểm-nối-điểm (site-to-site). 1. VPN Remote Access - Remote Access VPNs cho phép truy cập bất cứ lúc nào bằng Remote, mobile, và các thiết ... tunnel về mạng của họ. I. Giới Thiệu VPN 1. Khái niệm - Mạng riêng ảo hay VPN (viết tắt cho Virtual Private Network) là một mạng dành riêng để kết nối các máy tính của các công ty, tập đoàn hay các ... lại đóng vai _________________________________________________________________________ VIRTUAL PRIVATE NETWORK (VPN) Nhóm 18 Lớp: DHTH3 GV: Th.s Nguyễn Hòa Danh sách: 1. Đặng Hồng Hải 2. Hồ Thanh...

... Routing and Remote Access nhấn vào Remote Access Policies nhấn chuột phải vào Connections to Microsoft Routing and Remote Access server chọn Properties. Trên thẻ Setting chọn Grant remote access ... Routing and Remote Access 2. Nhấn chuột phải vào SIM01(Local) trong cây chương trình và chọn Configure and Enable Routing and Remote Access 3. Nhấn Next trên trang Routing and Remote Access Server ... Configure and Enable Routing and Remote Access. 8. Trên trang Welcome to the Routing and Remote Access Server Setup Wizard, nhấn Next. 9. Trên trang Configuration, Remote access (dial-up or VPN) được...

... gain local access to the laptop, and discovers that it is automatically connecting to a remote network via IPSec. This provides the hacker remote access to the private network, so he uses network ... services to keep your network safe. However, most modern VPN systems are combined with firewalls in a single device. Virtual Private Networking Explained Virtual Private Networks solve the problem ... passwords. The 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...

... Routing and Remote Access filters restrict:  Internet access to private network resources, such as servers.  Private network user access to Internet-based resources, such as partner networks ... segments or between the private network and public networks. Placing Routers Within the Private Network You need to place routers within the private network so that:  The network traffic is isolated ... Solution for Private Network Connectivity 5 Restricting Internet and Private Network Traffic Routing and Remote Access allows you to restrict the traffic between private network segments,...

... ip_address . 640-605 Remote Access 3.0 www.testking.com - 1 - 640-605 Study Guide Remote Access 3.0 (Building Cisco Remote Access Networks) Version 1 640-605 Remote Access 3.0 www.testking.com ... corporations to include dial-up access to network resources for remote users has created a high demand for point-to-point technologies. Telecommuting personnel require access to network devices and information ... initialize the network layer protocols. Transmission of network layer protocols can be held until this phase is complete. • The network layer protocol configuration negotiation occurs. Network layer...

... public internetwork in a manner that emulates the properties of a point-to-point private link. The act of configuring and creating a virtual private network is known as virtual private networking. ... the internetwork appears to the user as a private network communication—despite the fact that this communication occurs over a public internetwork—hence the name virtual private network. VPN ... creation of VPNs from anywhere, networks need strong security features to prevent unwelcome access to private networks and to protect private data as it traverses the public network. User authentication...

... Solution for Remote Access 19 Restricting Remote User Access to the Private Network  Specify Remote Access Policies  Centralize Remote Access Policies RADIUS Client Remote Access Policies Central Office RADIUS Server ISP Partner Network Internet RADIUS Client Remote ... and Remote Access VPN-based servers that support the remote access clients. The remote access users are experiencing difficulty in connecting to the private network because the remote access ... with remote access policies. Slide Objective To describe how to restrict remote user access to private network resources. Lead-in To restrict remote user access to the private network, ...