How EIGRP behaves over a GRE tunnel compared to a directly connected network?
A. EIGRP will use the same administrative distance and metric calculation for the GRE tunnel. The cost calculation is based on bandwidth and delay. The bandwidth and delay of the GRE tunnel will be taken from the tunnel interface configured on the router. The tunnel will also be treated like a directly connected network. If there are two paths to reach a network either through a VLAN interface or tunnel interface, EIGRP prefers the Virtual-Access Interface (VAI) VLAN interface because the VLAN interface has greater bandwidth than the tunnel interface. In order to influence the routing through the tunnel interface, increase the bandwidth parameter of the tunnel interface, or increase the delay parameter of the VLAN interface.