Chapter 25 IPSec VPN
ZyWALL USG 300 User’s Guide
511
These modes are illustrated below.
In tunnel mode, the ZyWALL uses the active protocol to encapsulate the entire IP
packet. As a result, there are two IP headers:
• Outside header: The outside IP header contains the IP address of the ZyWALL or
remote IPSec router, whichever is the destination.
• Inside header: The inside IP header contains the IP address of the computer
behind the ZyWALL or remote IPSec router. The header for the active protocol
(AH or ESP) appears between the IP headers.
In transport mode, the encapsulation depends on the active protocol. With AH, the
ZyWALL includes part of the original IP header when it encapsulates the packet.
With ESP, however, the ZyWALL does not include the IP header when it
encapsulates the packet, so it is not possible to verify the integrity of the source IP
address.
IPSec SA Proposal and Perfect Forward Secrecy
An IPSec SA proposal is similar to an IKE SA proposal (see
), except that you also have the choice whether or not the ZyWALL and
remote IPSec router perform a new DH key exchange every time an IPSec SA is
established. This is called Perfect Forward Secrecy (PFS).
If you enable PFS, the ZyWALL and remote IPSec router perform a DH key
exchange every time an IPSec SA is established, changing the root key from which
encryption keys are generated. As a result, if one encryption key is compromised,
other encryption keys remain secure.
If you do not enable PFS, the ZyWALL and remote IPSec router use the same root
key that was generated when the IKE SA was established to generate encryption
keys.
The DH key exchange is time-consuming and may be unnecessary for data that
does not require such security.
Figure 367
VPN: Transport and Tunnel Mode Encapsulation
Original Packet
IP Header TCP
Header
Data
Transport Mode Packet
IP Header AH/ESP
Header
TCP
Header
Data
Tunnel Mode Packet
IP Header AH/ESP
Header
IP Header TCP
Header
Data
Содержание USG-300 - V2.20 ED 2
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Страница 30: ...Table of Contents ZyWALL USG 300 User s Guide 30 ...
Страница 31: ...31 PART I User s Guide ...
Страница 32: ...32 ...
Страница 38: ...Chapter 1 Introducing the ZyWALL ZyWALL USG 300 User s Guide 38 ...
Страница 46: ...Chapter 2 Features and Applications ZyWALL USG 300 User s Guide 46 ...
Страница 64: ...Chapter 3 Web Configurator ZyWALL USG 300 User s Guide 64 ...
Страница 74: ...Chapter 4 Installation Setup Wizard ZyWALL USG 300 User s Guide 74 ...
Страница 116: ...Chapter 6 Configuration Basics ZyWALL USG 300 User s Guide 116 ...
Страница 128: ...Chapter 7 Tutorials ZyWALL USG 300 User s Guide 128 Figure 73 Configuration Network Interface WLAN Add ...
Страница 184: ...Chapter 7 Tutorials ZyWALL USG 300 User s Guide 184 ...
Страница 221: ...Chapter 8 L2TP VPN Example ZyWALL USG 300 User s Guide 221 ...
Страница 222: ...Chapter 8 L2TP VPN Example ZyWALL USG 300 User s Guide 222 ...
Страница 223: ...223 PART II Technical Reference ...
Страница 224: ...224 ...
Страница 238: ...Chapter 9 Dashboard ZyWALL USG 300 User s Guide 238 ...
Страница 282: ...Chapter 10 Monitor ZyWALL USG 300 User s Guide 282 ...
Страница 303: ...Chapter 13 Interfaces ZyWALL USG 300 User s Guide 303 Figure 269 Configuration Network Interface Ethernet Edit ...
Страница 320: ...Chapter 13 Interfaces ZyWALL USG 300 User s Guide 320 Figure 275 Configuration Network Interface Cellular Add ...
Страница 330: ...Chapter 13 Interfaces ZyWALL USG 300 User s Guide 330 Figure 278 Configuration Network Interface WLAN Add No Security ...
Страница 345: ...Chapter 13 Interfaces ZyWALL USG 300 User s Guide 345 Figure 286 Configuration Network Interface VLAN Edit ...
Страница 355: ...Chapter 13 Interfaces ZyWALL USG 300 User s Guide 355 Figure 288 Configuration Network Interface Bridge Add ...
Страница 378: ...Chapter 14 Trunks ZyWALL USG 300 User s Guide 378 ...
Страница 394: ...Chapter 15 Policy and Static Routes ZyWALL USG 300 User s Guide 394 ...
Страница 408: ...Chapter 16 Routing Protocols ZyWALL USG 300 User s Guide 408 ...
Страница 428: ...Chapter 19 NAT ZyWALL USG 300 User s Guide 428 ...
Страница 433: ...Chapter 20 HTTP Redirect ZyWALL USG 300 User s Guide 433 ...
Страница 434: ...Chapter 20 HTTP Redirect ZyWALL USG 300 User s Guide 434 ...
Страница 456: ...Chapter 23 Authentication Policy ZyWALL USG 300 User s Guide 456 ...
Страница 474: ...Chapter 24 Firewall ZyWALL USG 300 User s Guide 474 ...
Страница 481: ...Chapter 25 IPSec VPN ZyWALL USG 300 User s Guide 481 Figure 355 Configuration VPN IPSec VPN VPN Connection Edit IKE ...
Страница 492: ...Chapter 25 IPSec VPN ZyWALL USG 300 User s Guide 492 Figure 358 Configuration VPN IPSec VPN VPN Gateway Edit ...
Страница 515: ...Chapter 25 IPSec VPN ZyWALL USG 300 User s Guide 515 ...
Страница 516: ...Chapter 25 IPSec VPN ZyWALL USG 300 User s Guide 516 ...
Страница 529: ...Chapter 26 SSL VPN ZyWALL USG 300 User s Guide 529 ...
Страница 530: ...Chapter 26 SSL VPN ZyWALL USG 300 User s Guide 530 ...
Страница 540: ...Chapter 27 SSL User Screens ZyWALL USG 300 User s Guide 540 ...
Страница 542: ...Chapter 28 SSL User Application Screens ZyWALL USG 300 User s Guide 542 ...
Страница 550: ...Chapter 29 SSL User File Sharing ZyWALL USG 300 User s Guide 550 ...
Страница 635: ...Chapter 34 IDP ZyWALL USG 300 User s Guide 635 ...
Страница 636: ...Chapter 34 IDP ZyWALL USG 300 User s Guide 636 ...
Страница 646: ...Chapter 35 ADP ZyWALL USG 300 User s Guide 646 Figure 448 Profiles Protocol Anomaly ...
Страница 657: ...Chapter 35 ADP ZyWALL USG 300 User s Guide 657 ...
Страница 658: ...Chapter 35 ADP ZyWALL USG 300 User s Guide 658 ...
Страница 690: ...Chapter 37 Content Filter Reports ZyWALL USG 300 User s Guide 690 ...
Страница 708: ...Chapter 38 Anti Spam ZyWALL USG 300 User s Guide 708 ...
Страница 730: ...Chapter 39 Device HA ZyWALL USG 300 User s Guide 730 ...
Страница 746: ...Chapter 40 User Group ZyWALL USG 300 User s Guide 746 ...
Страница 752: ...Chapter 41 Addresses ZyWALL USG 300 User s Guide 752 ...
Страница 764: ...Chapter 43 Schedules ZyWALL USG 300 User s Guide 764 ...
Страница 780: ...Chapter 45 Authentication Method ZyWALL USG 300 User s Guide 780 ...
Страница 802: ...Chapter 46 Certificates ZyWALL USG 300 User s Guide 802 ...
Страница 814: ...Chapter 48 SSL Application ZyWALL USG 300 User s Guide 814 ...
Страница 820: ...Chapter 49 Endpoint Security ZyWALL USG 300 User s Guide 820 Figure 534 Configuration Object Endpoint Security Add ...
Страница 824: ...Chapter 49 Endpoint Security ZyWALL USG 300 User s Guide 824 ...
Страница 876: ...Chapter 50 System ZyWALL USG 300 User s Guide 876 ...
Страница 916: ...Chapter 54 Reboot ZyWALL USG 300 User s Guide 916 ...
Страница 918: ...Chapter 55 Shutdown ZyWALL USG 300 User s Guide 918 ...
Страница 938: ...Chapter 56 Troubleshooting ZyWALL USG 300 User s Guide 938 ...
Страница 946: ...Chapter 57 Product Specifications ZyWALL USG 300 User s Guide 946 ...
Страница 1118: ...Appendix F Open Software Announcements ZyWALL USG 300 User s Guide 1118 ...