Chapter 21 IPSec VPN
USG20(W)-VPN Series User’s Guide
354
21.4 VPN Concentrator
A VPN concentrator combines several IPSec VPN connections into one secure network.
Figure 229
VPN Topologies (Fully Meshed and Hub and Spoke)
In a fully-meshed VPN topology (
1
in the figure), there is a VPN connection between every pair of
routers. In a hub-and-spoke VPN topology (
2
in the figure), there is a VPN connection between
each spoke router (
B
,
C
,
D
, and
E
) and the hub router (
A
), which uses the VPN concentrator. The
VPN concentrator routes VPN traffic between the spoke routers and itself.
A VPN concentrator reduces the number of VPN connections that you have to set up and maintain in
the network. You might also be able to consolidate the policy routes in each spoke router,
depending on the IP addresses and subnets of each spoke.
However a VPN concentrator is not for every situation. The hub router is a single failure point, so a
VPN concentrator is not as appropriate if the connection between spoke routers cannot be down
occasionally (maintenance, for example). There is also more burden on the hub router. It receives
VPN traffic from one spoke, decrypts it, inspects it to find out to which spoke to route it, encrypts it,
and sends it to the appropriate spoke. Therefore, a VPN concentrator is more suitable when there is
a minimum amount of traffic between spoke routers.
21.4.1 VPN Concentrator Requirements and Suggestions
Consider the following when using the VPN concentrator.
• The local IP addresses configured in the VPN rules should not overlap.
• The concentrator must have at least one separate VPN rule for each spoke. In the local policy,
specify the IP addresses of the networks with which the spoke is to be able to have a VPN tunnel.
This may require you to use more than one VPN rule for each spoke.
• To have all Internet access from the spoke routers go through the VPN tunnel, set the VPN rules
in the spoke routers to use 0.0.0.0 (any) as the remote IP address.
• Your security policies can still block VPN packets.
1
2
Содержание ZyWall USG20-VPN
Страница 17: ...17 PART I User s Guide ...
Страница 18: ...18 ...
Страница 99: ...99 PART II Technical Reference ...
Страница 100: ...100 ...
Страница 151: ...Chapter 9 Interfaces USG20 W VPN Series User s Guide 151 Configuration Network Interface Ethernet Edit External Type ...
Страница 152: ...Chapter 9 Interfaces USG20 W VPN Series User s Guide 152 Configuration Network Interface Ethernet Edit External Type ...
Страница 154: ...Chapter 9 Interfaces USG20 W VPN Series User s Guide 154 Configuration Network Interface Ethernet Edit Internal Type ...
Страница 155: ...Chapter 9 Interfaces USG20 W VPN Series User s Guide 155 Figure 121 Configuration Network Interface Ethernet Edit OPT ...
Страница 156: ...Chapter 9 Interfaces USG20 W VPN Series User s Guide 156 Configuration Network Interface Ethernet Edit OPT ...
Страница 170: ...Chapter 9 Interfaces USG20 W VPN Series User s Guide 170 Figure 127 Configuration Network Interface PPP Add ...
Страница 178: ...Chapter 9 Interfaces USG20 W VPN Series User s Guide 178 Figure 129 Configuration Network Interface Cellular Add Edit ...
Страница 194: ...Chapter 9 Interfaces USG20 W VPN Series User s Guide 194 Figure 139 Configuration Network Interface VLAN Add Edit ...
Страница 206: ...Chapter 9 Interfaces USG20 W VPN Series User s Guide 206 Figure 141 Configuration Network Interface Bridge Add Edit ...
Страница 282: ...Chapter 15 UPnP USG20 W VPN Series User s Guide 282 Figure 190 Network Connections My Network Places Properties Example ...
Страница 340: ...Chapter 21 IPSec VPN USG20 W VPN Series User s Guide 340 Figure 226 Configuration VPN IPSec VPN VPN Connection Edit IKE ...
Страница 348: ...Chapter 21 IPSec VPN USG20 W VPN Series User s Guide 348 Figure 228 Configuration VPN IPSec VPN VPN Gateway Add Edit ...
Страница 378: ...Chapter 22 SSL VPN USG20 W VPN Series User s Guide 378 Create a Web Application SSL Application Object ...
Страница 591: ...Chapter 31 Log and Report USG20 W VPN Series User s Guide 591 Figure 418 Configuration Log Report Email Daily Report ...
Страница 659: ...Appendix B Legal Information USG20 W VPN Series User s Guide 659 Environmental Product Declaration ...