Question

A network engineer must keep the traffic of two customers, RED and BLUE, completely isolated across a single physical link between two routers, R1 and R2. Each router already has VRFs named RED and BLUE with the appropriate interfaces assigned. The engineer configures an 802.1Q trunk between R1 and R2 using subinterfaces. Which configuration step is required so that routing within each VRF is exchanged correctly across the link?

Accepted Answer

Assign each subinterface to the matching VRF and run a separate routing process (or address-family) per VRF over those subinterfaces

Answer

Enable MPLS on both routers so that VPN labels carry the RED and BLUE prefixes across the shared physical link

Answer

Configure a single global OSPF process on the physical interface and redistribute both VRFs into it

Answer

Create a GRE tunnel per VRF and place the physical interface in the default global routing table