Prestige 662HW Series User’s Guide
233
Chapter 19 VPN Screens
•
Main Mode
ensures the highest level of security when the communicating parties are
negotiating authentication (phase 1). It uses 6 messages in three round trips: SA
negotiation, Diffie-Hellman exchange and an exchange of nonces (a nonce is a random
number). This mode features identity protection (your identity is not revealed in the
negotiation).
•
Aggressive Mode
is quicker than
Main Mode
because it eliminates several steps when
the communicating parties are negotiating authentication (phase 1). However the trade-
off is that faster speed limits its negotiating power and it also does not provide identity
protection. It is useful in remote access situations where the address of the initiator is not
know by the responder and both parties want to use pre-shared key authentication.
19.11.2 Diffie-Hellman (DH) Key Groups
Diffie-Hellman (DH) is a public-key cryptography protocol that allows two parties to
establish a shared secret over an unsecured communications channel. Diffie-Hellman is used
within IKE SA setup to establish session keys. 768-bit (Group 1 -
DH1
) and 1024-bit (Group 2
–
DH2
) Diffie-Hellman groups are supported. Upon completion of the Diffie-Hellman
exchange, the two peers have a shared secret, but the IKE SA is not authenticated. For
authentication, use pre-shared keys.
19.11.3 Perfect Forward Secrecy (PFS)
Enabling PFS means that the key is transient. The key is thrown away and replaced by a brand
new key using a new Diffie-Hellman exchange for each new IPSec SA setup. With PFS
enabled, if one key is compromised, previous and subsequent keys are not compromised,
because subsequent keys are not derived from previous keys. The (time-consuming) Diffie-
Hellman exchange is the trade-off for this extra security.
This may be unnecessary for data that does not require such security, so PFS is disabled
(
None
) by default in the Prestige. Disabling PFS means new authentication and encryption
keys are derived from the same root secret (which may have security implications in the long
run) but allows faster SA setup (by bypassing the Diffie-Hellman key exchange).
19.12 Configuring Advanced IKE Settings
Click
Advanced
in the
VPN IKE
screen. This is the
VPN IKE- Advanced Setup
screen as
shown next.
Содержание P-662HW-63
Страница 6: ...Prestige 662HW Series User s Guide Customer Support 6...
Страница 7: ...Prestige 662HW Series User s Guide 7 Customer Support...
Страница 43: ...Prestige 662HW Series User s Guide 43 Introduction to DSL...
Страница 53: ...Prestige 662HW Series User s Guide 53 Chapter 1 Getting To Know Your Prestige...
Страница 59: ...Prestige 662HW Series User s Guide 59 Chapter 2 Introducing the Web Configurator...
Страница 77: ...Prestige 662HW Series User s Guide 77 Chapter 5 Password Setup...
Страница 89: ...Prestige 662HW Series User s Guide 89 Chapter 7 DMZ...
Страница 111: ...Prestige 662HW Series User s Guide 111 Chapter 8 Wireless LAN Setup...
Страница 127: ...Prestige 662HW Series User s Guide 127 Chapter 9 WAN Setup...
Страница 139: ...Prestige 662HW Series User s Guide 139 Chapter 10 Network Address Translation NAT Screens...
Страница 157: ...Prestige 662HW Series User s Guide 157 Chapter 13 Firewalls...
Страница 203: ...Prestige 662HW Series User s Guide 203 Chapter 16 Content Access Control...
Страница 211: ...Prestige 662HW Series User s Guide 211 Chapter 17 Anti Virus Packet Scan...
Страница 217: ...Prestige 662HW Series User s Guide 217 Chapter 18 Introduction to IPSec...
Страница 249: ...Prestige 662HW Series User s Guide 249 Chapter 20 Remote Management Configuration...
Страница 263: ...Prestige 662HW Series User s Guide 263 Chapter 21 Universal Plug and Play UPnP...
Страница 269: ...Prestige 662HW Series User s Guide 269 Chapter 22 Logs Screens...
Страница 295: ...Prestige 662HW Series User s Guide 295 Chapter 24 Maintenance...
Страница 301: ...Prestige 662HW Series User s Guide 301 Chapter 25 Introducing the SMT...
Страница 305: ...Prestige 662HW Series User s Guide 305 Chapter 26 Menu 1 General Setup...
Страница 319: ...Prestige 662HW Series User s Guide 319 Chapter 29 Wireless LAN Setup...
Страница 325: ...Prestige 662HW Series User s Guide 325 Chapter 30 Internet Access...
Страница 339: ...Prestige 662HW Series User s Guide 339 Chapter 32 Static Route Setup...
Страница 343: ...Prestige 662HW Series User s Guide 343 Chapter 33 Bridging Setup...
Страница 375: ...Prestige 662HW Series User s Guide 375 Chapter 36 Filter Configuration...
Страница 395: ...Prestige 662HW Series User s Guide 395 Chapter 39 System Information and Diagnosis...
Страница 411: ...Prestige 662HW Series User s Guide 411 Chapter 40 Firmware and Configuration File Maintenance...
Страница 417: ...Prestige 662HW Series User s Guide 417 Chapter 41 System Maintenance...
Страница 421: ...Prestige 662HW Series User s Guide 421 Chapter 42 Remote Management...
Страница 433: ...Prestige 662HW Series User s Guide 433 Chapter 44 Call Scheduling...
Страница 449: ...Prestige 662HW Series User s Guide 449 Chapter 46 SA Monitor...
Страница 453: ...Prestige 662HW Series User s Guide 453 Chapter 47 Internal SPTGEN...
Страница 459: ...Prestige 662HW Series User s Guide 459 Appendix A Pin Assignments Figure 290 Ethernet Cable Pin Assignments...
Страница 479: ...Prestige 662HW Series User s Guide 479 Appendix C IP Subnetting...
Страница 485: ...Prestige 662HW Series User s Guide 485 Appendix E Wireless LAN and IEEE 802 11...
Страница 492: ...Prestige 662HW Series User s Guide Appendix H Triangle Route 492...
Страница 493: ...Prestige 662HW Series User s Guide 493 Appendix H Triangle Route...
Страница 525: ...Prestige 662HW Series User s Guide 525 Appendix K Example Internal SPTGEN Screens...
Страница 527: ...Prestige 662HW Series User s Guide 527 Appendix L Command Interpreter...
Страница 529: ...Prestige 662HW Series User s Guide 529 Appendix M Firewall Commands...
Страница 533: ...Prestige 662HW Series User s Guide 533 Appendix N NetBIOS Filter Commands...
Страница 535: ...Prestige 662HW Series User s Guide 535 Appendix O Brute Force Password Guessing Protection...