Posts Tagged ‘get vpn’
Some time ago I mentioned that it is possible to configure a functional GET VPN scenario using just two routers. Normally, GET VPN requires a dedicated Key Server, which does not participate is user traffic encryption and only distributes keying information and encryption policies. All other routers – group members – register to the Key Server. A router could not register to itself when configured as a key server and group member simultaneously. However, there is a Key Server redundancy feature known as KOOP Key Servers that allows for two servers to synchronize the keying information and the group member to register to the redundant key servers.
Relying upon this feature, we may take two routers and configure them both in a KOOP key server pair. At the same time, every router is configured as a Group Member registering to another router. Since the keying information is being kept in sync, both routers will be able to properly exchange encrypted GET VPN traffic. Now, for the practical implementation we chose two directly connected routers: R4 and R5. GET VPN is supposed to encrypt traffic sent off respective VLAN4 and VLAN5 interfaces of these routers destined to the multicast groups in range 18.104.22.168/8. The IP addresses for VLAN4 and VLAN5 subnets are 173.X.4.0/24 and 173.X.5.0/24. Here is how we configure R4 for Key Server functionality. Notice the redundancy configuration using R5 as the peer.