We present a detailed study of the potential impact of BGP peering session attacks and the resulting exploitation of Route Flap Damping (RFD) that cause network-wide routing disruptions. We consider canonical grid as well as down-sampled realistic Autonomous System (AS) topologies and address the impact of various typical service provider routing policies. Our modeling focuses on three dimensions of routing performance sensitivity: (a) Protocol aware attacks (e.g., tuned to RFD), (b) Route selection policy, and (c) Attack-region topology. Analytical results provide insights into the nature of the problem and potential impact of the attacks. Detailed packet-level simulation results complement the analytical models and provide many additional insights into specific protocol interactions and timing issues. Finally, we quantify the potential effect of the BGP Graceful Restart mechanism as a partial mitigation of the BGP vulnerability to peering session attacks.