Chapter 20 IPSec VPN
The ZyWALL sends one or more proposals to the remote IPSec router. (In some devices, you can only set up 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, 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.
In most ZyWALLs, you can select one of the following encryption algorithms for each proposal. The algorithms are listed in order from weakest to strongest.
•Data Encryption Standard (DES) is a widely used method of data encryption. It applies a
•Triple DES (3DES) is a variant of DES. It iterates three times with three separate keys, effectively tripling the strength of DES.
•Advanced Encryption Standard (AES) is a newer method of data encryption that also uses a secret key. AES applies a
Some ZyWALLs also offer stronger forms of AES that apply
In most ZyWALLs, you can select one of the following authentication algorithms for each proposal. The algorithms are listed in order from weakest to strongest.
•MD5 (Message Digest 5) produces a
•SHA1 (Secure Hash Algorithm) produces a
See
The ZyWALL and the remote IPSec router use DH
Figure 262 IKE SA: Main Negotiation Mode, Steps 3 - 4: DH Key Exchange
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ZyWALL USG 100/200 Series User’s Guide |
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