VRFs and Shared Services Cheating with Junos
The shared services area of the network is meant to provide common services — such as DNS, DHCP, and Internet access — to multiple logical networks/VRFs/customers. Cisco publishes a validated design for shared services that describes the use of multiple virtual firewalls and routers to provide connectivity between the shared services module and the VRFs in the network. I'm going to describe a method of collapsing the shared services firewalls and virtual routers into a single instance running on a single box using some of the features found in Juniper's Junos platform.