HP HSR6800 Configuration Manual page 250

Figure 68 Network diagram for basic VPN networking scheme
In Figure 68, for example, the route target for VPN 1 is 100:1 on the PEs, while that for VPN 2 is
200:1. The two VPN 1 sites can communicate with each other, and the two VPN 2 sites can
communicate with each other. However, the VPN 1 sites cannot communicate with the VPN 2 sites.
Hub and spoke networking scheme
For a VPN where a central access control device is required and all users must communicate with
each other through the access control device, the hub and spoke networking scheme can be used to
implement the monitoring and filtering of user communications.
This networking scheme requires two route targets: one for the hub and the other for the spoke.
The route target setting rules for VPN instances of all sites on PEs are as follows:
•
On spoke PEs (that is, the PEs connected to spoke sites), set the export target attribute to
spoke and the import target attribute to Hub.
•
On the hub PE (that is, the PE connected to the hub site), specify two interfaces or
subinterfaces, one for receiving routes from spoke PEs, and the other for advertising routes to
spoke PEs. Set the import target attribute of the VPN instance for the former to Spoke, and the
export target attribute of the VPN instance for the latter to Hub.
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