Vuotoreittejä

Vuotoreittejä is a Finnish term used in the field of computer networking to describe route leaks in the Border Gateway Protocol (BGP). In this context, a route leak refers to the unintentional dissemination of IP prefixes from one autonomous system (AS) to another, resulting in prefixes being announced beyond their intended scope. The phenomenon is discussed in Finnish network literature as vuotoreittejä or vuotoreiteille tyypillisiä vääriä reittitulottoja, and it is typically viewed as a misconfiguration or policy flaw rather than a deliberate attack.

Route leaks occur when routing information learned from one neighbor is propagated to other neighbors in a way that bypasses the intended traffic engineering or access controls. Common scenarios include misconfigured iBGP and eBGP policies, improper redistribution of routes between VPNs or VRFs and the public Internet, or errors in route reflectors and filter lists. These leaks can cause prefixes to appear reachable through paths that are longer, less secure, or less reliable, and can lead to suboptimal routing, increased latency, or unintended traffic exposure.

The impact of vuotoreittejä can range from degraded performance to outages, and they may complicate traffic engineering and security monitoring. Detection relies on observing anomalies in BGP updates, such as sudden changes in AS paths or origin inconsistencies, and on corroborating data from route collectors, looking glasses, and Internet-wide monitoring services. Mitigation emphasizes strict prefix filtering, careful AS path filtering, validation and filtering of routes at network borders, and the use of mechanisms like RPKI and BGPsec where feasible to reduce the chance of leaking and to ensure route authenticity.