Chapter 18 IPSec VPN
ZyWALL 5/35/70 Series User’s Guide
356
The ZyWALL sends one or more proposals to the remote IPSec router. (In some devices, you
can set up only one proposal.) Each proposal consists of an encryption algorithm,
authentication algorithm, and DH key group that the ZyWALL wants to use in the IKE SA.
The remote IPSec router selects an acceptable proposal and sends the accepted proposal back
to the ZyWALL. If the remote IPSec router rejects all of the proposals (for example, if the
VPN tunnel is not configured correctly), the ZyWALL and remote IPSec router cannot
establish an IKE SA.
"
Both routers must use the same encryption algorithm, authentication
algorithm, and DH key group.
See the field descriptions for information about specific encryption algorithms, authentication
algorithms, and DH key groups. See
Section 18.3.1.1 on page 356
for more information about
DH key groups.
18.3.1.1 Diffie-Hellman (DH) Key Exchange
The ZyWALL and the remote IPSec router use a DH key exchange to establish a shared secret,
which is used to generate encryption keys for IKE SA and IPSec SA. In main mode, the DH
key exchange is done in steps 3 and 4, as illustrated below.
Figure 206
IKE SA: Main Negotiation Mode, Steps 3 - 4: DH Key Exchange
The DH key exchange is based on DH key groups. Each key group is a fixed number of bits
long. The longer the key, the more secure the encryption keys, but also the longer it takes to
encrypt and decrypt information. For example, DH2 keys (1024 bits) are more secure than
DH1 keys (768 bits), but DH2 encryption keys take longer to encrypt and decrypt.
18.3.1.2 Authentication
Before the ZyWALL and remote IPSec router establish an IKE SA, they have to verify each
other’s identity. This process is based on pre-shared keys and router identities.
In main mode, the ZyWALL and remote IPSec router authenticate each other in steps 5 and 6,
as illustrated below. Their identities are encrypted using the encryption algorithm and
encryption key the ZyWALL and remote IPSec router selected in previous steps.
Summary of Contents for ZyWALL 35 Series
Page 2: ......
Page 8: ...Safety Warnings ZyWALL 5 35 70 Series User s Guide 8 ...
Page 52: ...List of Tables ZyWALL 5 35 70 Series User s Guide 52 ...
Page 54: ...54 ...
Page 60: ...Chapter 1 Getting to Know Your ZyWALL ZyWALL 5 35 70 Series User s Guide 60 ...
Page 86: ...Chapter 2 Introducing the Web Configurator ZyWALL 5 35 70 Series User s Guide 86 ...
Page 140: ...Chapter 4 Tutorials ZyWALL 5 35 70 Series User s Guide 140 ...
Page 146: ...Chapter 5 Registration ZyWALL 5 35 70 Series User s Guide 146 ...
Page 148: ...148 ...
Page 160: ...Chapter 6 LAN Screens ZyWALL 5 35 70 Series User s Guide 160 ...
Page 173: ...Chapter 8 WAN Screens ZyWALL 5 35 70 Series User s Guide 173 Figure 93 NETWORK WAN General ...
Page 202: ...Chapter 8 WAN Screens ZyWALL 5 35 70 Series User s Guide 202 ...
Page 212: ...Chapter 9 DMZ Screens ZyWALL 5 35 70 Series User s Guide 212 ...
Page 242: ...242 ...
Page 274: ...Chapter 11 Firewall ZyWALL 5 35 70 Series User s Guide 274 ...
Page 294: ...Chapter 13 Configuring IDP ZyWALL 5 35 70 Series User s Guide 294 ...
Page 320: ...Chapter 15 Anti Spam ZyWALL 5 35 70 Series User s Guide 320 ...
Page 342: ...Chapter 16 Content Filtering Screens ZyWALL 5 35 70 Series User s Guide 342 ...
Page 350: ...Chapter 17 Content Filtering Reports ZyWALL 5 35 70 Series User s Guide 350 ...
Page 424: ...Chapter 19 Certificates ZyWALL 5 35 70 Series User s Guide 424 ...
Page 430: ...430 ...
Page 448: ...Chapter 21 Network Address Translation NAT ZyWALL 5 35 70 Series User s Guide 448 ...
Page 474: ...Chapter 24 Bandwidth Management ZyWALL 5 35 70 Series User s Guide 474 ...
Page 514: ...Chapter 26 Remote Management ZyWALL 5 35 70 Series User s Guide 514 ...
Page 533: ...533 PART V Reports Logs and Maintenance Reports 535 Logs Screens 547 Maintenance 575 ...
Page 534: ...534 ...
Page 551: ...Chapter 31 Logs Screens ZyWALL 5 35 70 Series User s Guide 551 Figure 334 LOGS Log Settings ...
Page 592: ...Chapter 32 Maintenance ZyWALL 5 35 70 Series User s Guide 592 ...
Page 594: ...594 Troubleshooting 751 Product Specifications 757 ...
Page 602: ...Chapter 33 Introducing the SMT ZyWALL 5 35 70 Series User s Guide 602 ...
Page 622: ...Chapter 35 WAN and Dial Backup Setup ZyWALL 5 35 70 Series User s Guide 622 ...
Page 628: ...Chapter 36 LAN Setup ZyWALL 5 35 70 Series User s Guide 628 ...
Page 634: ...Chapter 37 Internet Access ZyWALL 5 35 70 Series User s Guide 634 ...
Page 638: ...Chapter 38 DMZ Setup ZyWALL 5 35 70 Series User s Guide 638 ...
Page 642: ...Chapter 39 Route Setup ZyWALL 5 35 70 Series User s Guide 642 ...
Page 658: ...Chapter 41 Remote Node Setup ZyWALL 5 35 70 Series User s Guide 658 ...
Page 662: ...Chapter 42 IP Static Route Setup ZyWALL 5 35 70 Series User s Guide 662 ...
Page 700: ...Chapter 45 Filter Configuration ZyWALL 5 35 70 Series User s Guide 700 ...
Page 738: ...Chapter 50 Remote Management ZyWALL 5 35 70 Series User s Guide 738 ...
Page 746: ...Chapter 51 IP Policy Routing ZyWALL 5 35 70 Series User s Guide 746 ...
Page 766: ...766 ...
Page 770: ...Appendix A Hardware Installation ZyWALL 5 35 70 Series User s Guide 770 ...
Page 780: ...Appendix C Removing and Installing a Fuse ZyWALL 5 35 70 Series User s Guide 780 ...
Page 802: ...Appendix D Setting up Your Computer s IP Address ZyWALL 5 35 70 Series User s Guide 802 ...
Page 816: ...Appendix F Common Services ZyWALL 5 35 70 Series User s Guide 816 ...
Page 852: ...Appendix J Importing Certificates ZyWALL 5 35 70 Series User s Guide 852 ...
Page 856: ...Appendix K Legal Information ZyWALL 5 35 70 Series User s Guide 856 ...
Page 862: ...Appendix L Customer Support ZyWALL 5 35 70 Series User s Guide 862 ...