Flexsealing BGP Against Route Leaks: Peerlock Active Measurement and Analysis

TL;DR

This paper evaluates Peerlock, a BGP route leak mitigation system, through live measurements and simulations, showing its current deployment reduces leaks and strategic expansion could nearly eliminate them.

Contribution

It provides the first live Internet measurements of Peerlock deployment and quantifies its effectiveness in reducing route leaks through simulations.

Findings

48% of Peerlock filters deployed among Tier 1 networks

Current Peerlock deployment restricts Tier 1 leaks to 10% or fewer networks

Strategic deployment of Peerlock-lite can mitigate 80% of simulated Tier 1 leaks

Abstract

BGP route leaks frequently precipitate serious disruptions to interdomain routing. These incidents have plagued the Internet for decades while deployment and usability issues cripple efforts to mitigate the problem. Peerlock, introduced in 2016, addresses route leaks with a new approach. Peerlock enables filtering agreements between transit providers to protect their own networks without the need for broad cooperation or a trust infrastructure. We outline the Peerlock system and one variant, Peerlock-lite, and conduct live Internet experiments to measure their deployment on the control plane. Our measurements find evidence for significant Peerlock protection between Tier 1 networks in the peering clique, where 48% of potential Peerlock filters are deployed, and reveal that many other networks also deploy filters against Tier 1 leaks. To guide further deployment, we also quantify Peerlock's impact on route leaks both at currently observed levels and under hypothetical future deployment scenarios via BGP simulation. These experiments reveal present Peerlock deployment restricts Tier 1 leak export to 10% or fewer networks for 40% of simulated leaks. Strategic additional Peerlock-lite deployment at all large ISPs (fewer than 1% of all networks), in tandem with Peerlock within the peering clique as deployed, completely mitigates 80% of simulated Tier 1 route leaks.