The Research and Analysis on Controlling the Number of VPN Routes Through VPN Prefix Outbound Route Filter (ORF) Mechanism

We proposed a Virtual Private Network (VPN) route control mechanism by extending the Outbound Route Filter (ORF). A new ORF type which is named VPN Prefix ORF is defined to carry the Route Distinguisher (RD), Source Provider Edge (PE) and other features of the “offending” VPN routes. The scenarios where a device simultaneously receives a large number of VPN routes exceeding the threshold in both intra-domain and inter-domain were simulated to verify the effect of VPN Prefix ORF mechanism. The CPU utilization, memory consumption, and routing convergence time were studied in detail to investigate whether the VPN mechanism can reduce the pressure on PE while not impose excessive burden on Route Reflector (RR). The results showed that VPN Prefix ORF mechanism can effectively prevent device resources from being occupied by a large number of unexpected VPN routes while not placing too much burden on RR.