HP Intelligent Management Center Licenses - Manual (Page 38)

simplest case, all users in a VPN form a closed user group. They can forward traffic to each other
but cannot communicate with any user outside the VPN. For this networking scheme, you need to
assign a VPN target to each VPN for identifying the export target attribute and import target
attribute of the VPN. Moreover, this VPN target cannot be used by any other VPNs.
1. Full-Mesh VPN or Simple VPN
In the simplest case, all users in a VPN form a closed user group. They can forward traffic to
each other but cannot communicate with any user outside the VPN. For this networking scheme,
you need to assign a VPN target to each VPN for identifying the export target attribute and
import target attribute of the VPN. Moreover, this VPN target cannot be used by any other
VPNs.
2. Hub-Spoke VPN (Central Services)
For a VPN where there is a server and all sites can communicate with the server, but cannot
communicate with each other, the hub and spoke networking scheme can be used. In the
following figure, the export target attribute of site 3 working as the server must be the same
with the import target attribute of site 1 and site 2, the import target attribute of site 3 must
be the same with the export target attribute of site 1 and site 2, and the import and export
target attribute cannot be the same. All the other sites except the site working as the server
adopt the same configurations.
38 MPLS Manager