Configurare VPN e Accesso remoto con Small Business Server 2003

1. Configurare VPN e Accesso remoto con Small Business Server 2003 5 maggio 2005 - 10:30

2. Agenda • VPN Basics • La protezione delle comunicazioni di rete • Encryption overview • VPN a confronto • Client-to-LAN • LAN-to-LAN • VPN in dettaglio • tunneling protocol • authentication • encryption • Le tecnologie di Windows Small Business Server 2003 per VPN Client-to-LAN Live Demo...

3. Che cosa è una VPN ? • Dal sito di Windows Server 2003 “Microsoft defines a virtual private network as the extension of a private network that encompasses links across shared or public networks like the Internet.” • http://www.microsoft.com/windowsserver2003/techinfo/overview/vpnfaq.mspx

4. IdentitySpoofing Man-in-the-Middle DataModification NetworkMonitoring Password-based Quali problemi abbiamo con una comunicazione di rete che usa connettività pubblica come Internet?

5. Encrypted IP Packet La soluzione: la cifratura dei dati trasmessi • Encrypts Data at the Application Layer • SSL • TLS • Encrypts Data at the Network Layer • Tunneling Protocol • IPSec

6. Virtual Private Networks (VPN) una applicazione delle tecnologie di encryption

7. VPN Basics • Una tecnologia di encryption • Un metodo/protocollo di Tunneling • Una modalità di connessione e trasporto(Client-to-LAN, LAN-to-LAN) • Un insieme di definizioni per • IP Addressing • Authentication • Authorization • Auditing

8. Crittografia • Encryption Keys & Algorithms • Una tecnologia molto antica Encrypted IP Packet

9. Encryption Keys

10. Utilizzi dell’encryption • implementa la riservatezza delle comunicazioni • fornisce delle tecniche per realizzare l’autenticazione dei soggetti della comunicazione

11. Symmetric encryption: • Usa la stessa chiave per cifrare e decifrare • E’ spesso referenziata come bulk encryption • E’ intrinsicamente vulnerabile per il concetto di “Shared secret”: la chiave è condivisa Symmetric Encryption Original Data Cipher Text Original Data

12. Utilizzi della symmetric encryption • Cifratura dei canali di trasmissione • Semplicità • Prestazioni • Gestione delle session-key dei protocolli sicuri • SSL • Kerberos • ...

13. Asymmetric (Public Key) Encryption

14. Utilizzi della Asymmetric encryption • Riservatezza delle comunicazioni (PK Encryption) • spesso in congiunzione con session key simmetriche • Identificazione degli estremi (soggetti) della comunicazione (PK Authentication) • Algoritmi più complessi • Meno efficente della symmetric • Per un uso libero richiede la distribuzione/pubblicazione delle chiavi pubbliche

15. 2 Encrypted Message is Sent Over Network 3A78 1 Alice Encrypts Message with Bob’s Public Key. Data 3 Bob Decrypts Message with Bob’s Private Key. Public Key Encryption Data 3A78

16. 2 Message is Sent Over Network ~*~*~*~ 1 Alice Signs Message with Her Private Key. 3 Bob Validates Message is From Alice with Alice’s Public Key. Public Key Authentication ~*~*~*~ ~*~*~*~

17. Dalla teoria alla pratica...

18. Internet VPN Client-to-LAN:Connecting Remote Users to a Corporate Network Corporate Network VPN ServerComputer VPN Tunnel Remote User

19. Internet VPN LAN-to-LAN:Connecting Remote Networks to a Local Network Local Network VPN ServerComputer VPN Tunnel VPN ServerComputer Remote Network

20. VPN a confronto: LAN-to-LAN • prevede l’utilizzo di apparati/server che gestiscono la comunicazione vpn e fanno da gateway tra le due reti • encryption applicata solo nelle comunicazioni tra i gateway (tunnel-endpoint) • encryption simmetrica di tipo “Shared-Key” • IP Addressing  progettare

21. VPN a confronto: Client-to-LAN • è una tipica connessione uno (gateway/Access Point) a molti (Client) • encryption applicata nelle comunicazioni tra il gateway ed N client • encryption di tipo “Shared-Key” non adeguata (distribuzione della chiave in N posti!) • può usare protocolli PPP-based (PPTP, L2TP) • per usare IPsec richiede tecniche di Asymmetric encryption (PKI, certificati, ...) • IP Addressing  semplice ed integrato

22. Internetwork Must Be IP Based No Header Compression No Tunnel Authentication Built-in PPP Encryption Virtual Private Network Protocols PPTP* L2TP** Internetwork Can Be IP, Frame Relay, X.25, or ATM Based Header Compression Tunnel Authentication Uses IPSec Encryption Internet Client Server PPTP or L2TP *PPTP: rfc 2637 - **L2TP: rfc 2661

23. Selecting a Tunneling Protocol Features Tunneling Protocol L2TP/ IPSec PPTP IPSec Tunnel Mode

24. Authentication Protocols • Standard Authentication Protocols • Extensible Authentication Protocols

25. Standard Authentication Protocols Protocol Security Use when PAP Low The client and server cannot negotiate using more secure validation SPAP Medium Connecting a Shiva LANRover and Windows 2000–based client or a Shiva client and a Windows 2000–based remote access server CHAP High You have clients that are not running Microsoft operating systems MS-CHAP High You have clients running Windows NT version 4.0 and later or, Microsoft Windows 95 and later MS-CHAP v2 High You have dial-up clients running Windows 2000, or VPN clients running Windows NT 4.0 or Windows 98

26. Authentication

27. Extensible Authentication Protocols • Allows the Client and Server to Negotiate the Authentication Method That They Will Use • Supports Authentication by Using • MD5-CHAP • Transport Layer Security (TLS) • PEAP, Smartcard, ... • Ensures Support of Future Authentication Methods Through an API

28. Encryption Protocols Members of this group dial-in profile can use IPSec 56-bit Data Encryption Standard (DES) or MPPE 40-bit data encryption Members of this group dial-in profile can use IPSec 56-bit DES or MPPE 56-bit data encryption Members of this group dial-in profile can use IPSec Triple DES (3DES) or MPPE 128-bit data encryption

29. Windows Small Business Server 2003 VPN setup & configuration

30. To Do List

31. 4 VPN server transfers data 3 VPN server checks the directory to authenticate and authorize the caller 1 VPN client calls the VPN server 2 VPN server answers the call VPN Client-to-LAN A VPN extends the capabilities of a private network to encompass links across shared or public networks, such as the Internet, in a manner that emulates a point-to-point link Windows Small Business Server VPN Client VPN Server

32. Architettura di deployment consigliata SBS è (anche) unF i r e w a l l ! ! ! Posizioniamolo come tale nella rete Internet rete pubblica(es: 193.205.245.24/29) xDSL Fibra ottica ISDN ... .2 Internet Router (ISP) azienda.local SBS rete pubblica (con NAT)(es: 192.168.0.0/24) rete privata 192.168.16.0/24

33. Windows Small Business Server Remote Access Wizard This wizard provides on-screen instructions for configuring your server for: VPN connections Dial-up connections Both VPN and dial-up connections After clicking Finish, the wizard: Configures the server according to your selected settings Creates the Client Connection Manager configuration file Configures the remote access policy to allow members of the Mobile Users group to use remote access

40. RASW • Client config (RWW) • RRAS configuration overview

41. Sicurezza e controllo • Remote Access Account Lockout (KB816118) • Authorizing VPN Connections (Dial-in) • Remote Access Policy Profile Packet Filtering • Accounting, Auditing, and Monitoring

42. Riferimenti e risorse • Risorse tecniche per Windows Small Business Server 2003http://www.microsoft.com/italy/windowsserver2003/sbs/techinfo/default.mspx • MOC Course 2395: Design, Deploy, and Manage a Network Solution for a Small and Medium Businesshttp://www.microsoft.com/traincert/syllabi/2395AFinal.asp • Exam 70-282: Design, Deploy, and Manage a Network Solution for a Small- and Medium-Sized Businesshttp://www.microsoft.com/learning/exams/70-282.asp

43. Riferimenti e risorse • Virtual Private Networks for Windows Server 2003http://www.microsoft.com/windowsserver2003/technologies/networking/vpn/default.mspx • Virtual Private Networking with Windows Server 2003: Deploying Remote Access VPNshttp://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/networking/vpndeplr.mspx • Virtual Private Networking with Windows Server 2003: Deploying Site-to-Site VPNshttp://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/networking/vpndpls2.mspx

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45. © 2004 Microsoft Corporation. All rights reserved. This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.