Quick Reference Guide

ADSL2+ Modem Wireless Router DG834G Reference Manual
6-4 Virtual Private Networking
v2.0, September 2007
• Will either endpoint use fully qualified domain names (FQDNs)? FQDNs supplied by
Dynamic DNS providers (see “Using a Fully Qualified Domain Name (FQDN)” on page B-7)
can allow a VPN endpoint with a dynamic IP address to initiate or respond to a tunnel request.
Otherwise, the side using a dynamic IP address must always be the initiator.
• Which method will you use to configure your VPN tunnels?
– The VPN Wizard using VPNC defaults (see Table 6-2)
– The typical automated Internet Key Exchange (IKE) setup (see “Using Auto Policy to
Configure VPN Tunnels” on page 6-32)
– A manual keying setup in which you must specify each phase of the connection (see
“Using Manual Policy to Configure VPN Tunnels” on page 6-41)?
• What level of IPSec VPN encryption will you use?
– DES. The Data Encryption Standard (DES) processes input data that is 64 bits wide,
encrypting these values using a 56-bit key. Faster but less secure than 3DES.
– 3DES. Triple DES achieves a higher level of security by encrypting the data three times
using DES with three different, unrelated keys.
• What level of authentication will you use?
– MDS. 128 bits, faster but less secure.
– SHA-1. 160 bits, slower but more secure.
Table 6-2. Parameters Recommended by the VPNC and Used in the VPN Wizard
Parameter Factory Default
Secure Association Main Mode
Authentication Method Pre-shared Key
Encryption Method 3DES
Authentication Protocol SHA-1
Diffie-Hellman (DH) Group Group 2 (1024 bit)
Key Life 8 hours
IKE Life Time 1 hour