User's Manual
Chapter 16 VPN
ADSL Series User’s Guide
220
WAN IP addresses of their IPSec routers. The telecommuters must all use the same IPSec
parameters but the local IP addresses (or ranges of addresses) should not overlap.
Figure 115 Telecommuters Sharing One VPN Rule Example
16.6.11.2 Telecommuters Using Unique VPN Rules Example
In this example the telecommuters (A, B and C in the figure) use IPSec routers with domain names
that are mapped to their dynamic WAN IP addresses (use Dynamic DNS to do this).
With aggressive negotiation mode (see Section 16.6.6 on page 217), the ZyXEL Device can use the
ID types and contents to distinguish between VPN rules. Telecommuters can each use a separate
VPN rule to simultaneously access a ZyXEL Device at headquarters. They can use different IPSec
parameters. The local IP addresses (or ranges of addresses) of the rules configured on the ZyXEL
Device at headquarters can overlap. The local IP addresses of the rules configured on the
telecommuters’ IPSec routers should not overlap.
See the following table and figure for an example where three telecommuters each use a different
VPN rule for a VPN connection with a ZyXEL Device located at headquarters. The ZyXEL Device at
headquarters (HQ in the figure) identifies each incoming SA by its ID type and content and uses the
appropriate VPN rule to establish the VPN connection.
The ZyXEL Device at headquarters can also initiate VPN connections to the telecommuters since it
can find the telecommuters by resolving their domain names.
Table 72 Telecommuters Sharing One VPN Rule Example
FIELDS TELECOMMUTERS HEADQUARTERS
My IP Address: 0.0.0.0 (dynamic IP address
assigned by the ISP)
Public static IP address
Secure Gateway IP
Address:
Public static IP address 0.0.0.0 With this IP address only
the telecommuter can initiate the IPSec
tunnel.
Local IP Address: Telecommuter A: 192.168.2.12
Telecommuter B: 192.168.3.2
Telecommuter C: 192.168.4.15
192.168.1.10
Remote IP
Address:
192.168.1.10 0.0.0.0 (N/A)
LAN
192.168.2.12
LAN
192.168.3.2
LAN
192.168.4.15
A
B
C
LAN
192.168.1.10
HQ