Siemens 5881 - Manual (Page 75)

SIEMENS 5881 Broadband Internet Router
User’s Guide Chapter 6 Security Setup
IKE/IPSec Configuration
SIEMENS 69
IKE Proposals Definition
IKE I proposals specify how packets will be encrypted/authenticated for Phase I. To define a new IKE proposal:
1. Click Create next to IKE Proposals from the Advanced IKE/IPSec Setup page. This displays the IKE
Proposal Definition page.
2. In IKE Proposal Name, enter a logical name for the IKE Proposal Definition. This name is of no
importance to the remote IKE peer.
3. From the Message Authentication Scheme drop-down menu, select one of the following hashing
(authentication) options to use to validate IKE Phase I exchange:
• MD5: Performs message authentication using Message Digest 5.
• SHA1: Performs message authentication using Secure Hashing Algorithm 1 (default).
4. From the Diffie-Hellman (Oakley) Group drop-down menu, select one of the following Diffie-Hellman key
generation groups to use during IKE Phase I exchange:
• Group 1: Uses Diffie-Hellman Group 1 (768 bits).
• Group 2: Uses Diffie-Hellman Group 2 (1024 bits).
5. From the Encryption Type drop-down menu, select one of the following encryption types to use during
IKE Phase II (Quick Mode) exchange:
• DES: Encrypts using a 56-bit key.
• 3-DES: Encrypts using three 56-bit keys to produce 168-bit encryption.
• AES: Encrypts using a 128-, 192-, or 256-bit key.
6. If you selected AES as the encryption type, specify the key bit size to use in Key Length. This can be 128,
192, or 256.
7. In Phase I Proposal Lifetime, enter the number of seconds after which the Phase I negotiation expires.
The default is 1800 seconds. Once this time is elapsed, the system will renegotiate the IKE connection.
8. Click Apply.