The internet feels permanent. Stable. Almost geographic.
But underneath the surface, it runs on trust — and that trust is surprisingly fragile.
Border Gateway Protocol (BGP) is the system that allows networks to tell each other where traffic should go. It’s often described as the “postal service” of the internet. In reality, it’s closer to a handshake agreement between thousands of independent operators.
And that handshake can be abused.
What BGP Actually Does
Every network on the internet announces which IP address ranges it controls. These announcements propagate across routers worldwide. When everything works correctly, traffic flows to the right destination.
But BGP was designed in a different era — one where participants were assumed to be cooperative. It does not include strong built-in authentication. If a network announces a route it does not actually own, other networks may believe it.
That’s the core weakness.
What Is BGP Hijacking?
BGP hijacking happens when an autonomous system falsely announces ownership of IP prefixes belonging to another network. Once the false announcement propagates, traffic can be silently rerouted, dropped, or inspected before being forwarded.
This can happen intentionally — as part of espionage or traffic interception — or accidentally, through misconfiguration.
Once those false routes propagate, traffic may be:
- redirected through the attacker’s network
- blackholed (dropped entirely)
- inspected before being forwarded
- partially disrupted
And it can happen fast.
Route propagation across global routers can take minutes. In that time, a large portion of internet traffic can be silently rerouted.
Not a Theoretical Risk
There have been multiple real-world cases.
In 2008, a Pakistani ISP attempting to block YouTube domestically accidentally hijacked YouTube’s prefixes globally, causing a worldwide outage.
In 2018, traffic intended for Amazon Route 53 was hijacked, enabling attackers to redirect cryptocurrency users to malicious infrastructure.
These weren’t cinematic cyberattacks. They were routing announcements accepted as legitimate.
The pattern is familiar: infrastructure designed for cooperation now operates in a threat environment.
Why BGP Trust Still Exists
If BGP is so vulnerable, why hasn’t it been replaced?
Because the internet is not centrally governed. It is a federation of networks. BGP works because it is simple and widely supported. Replacing it would require global coordination across thousands of operators.
Security extensions like RPKI (Resource Public Key Infrastructure) have been introduced to validate route ownership. Adoption is growing — but not universal.
Which means trust is still the default.
The Speed of Propagation
One of the most underestimated aspects of BGP hijacking is speed.
Announcements propagate quickly. Routers update tables. Traffic shifts.
Detection, however, is slower. Monitoring systems must notice anomalies. Engineers must verify ownership. Mitigation steps must be coordinated.
That asymmetry — rapid impact, slower correction — is what makes BGP hijacking dangerous.
It mirrors a broader pattern discussed in When a Single API Failure Breaks Thousands of Apps — tightly coupled systems propagate disruption faster than humans can respond.
Centralization Amplifies the Risk
In the early internet, traffic paths were more distributed. Today, large cloud providers, CDNs, and global platforms concentrate enormous volumes of traffic.
When a major prefix is hijacked, the blast radius can be enormous.
We explored structural fragility in The Day Facebook Went Offline: A Case Study in Centralization. BGP hijacking operates at a lower layer — but the principle is the same: concentration increases systemic impact.
If authentication, cloud hosting, and DNS are consolidated into a handful of providers, rerouting traffic for even minutes can affect thousands of services.
Accidental vs Intentional Hijacks
Not all hijacks are malicious.
Some are configuration errors. An engineer mistypes a prefix length. A route filter is misapplied. A small ISP mistakenly announces a broader route than intended.
Because BGP prefers more specific routes, even a small announcement can override legitimate ones.
Other hijacks are deliberate. Traffic interception can enable surveillance. Short-lived hijacks can extract credentials. Cryptocurrency infrastructure has been a repeated target.
The distinction matters legally. Technically, the effect is similar.
Can It Be Fixed?
Mitigation strategies exist:
- RPKI for route validation
- strict route filtering by ISPs
- prefix monitoring and anomaly detection
- shorter propagation windows
But none of these eliminate the underlying design reality: BGP assumes cooperation.
The internet was not built with adversarial routing at its core. Security layers have been added incrementally.
Incremental security often trails incremental complexity.
The Structural Lesson
BGP hijacking is not just a networking issue. It is a governance issue.
It shows how foundational systems rely on distributed trust. It reveals how fast infrastructure-level failures can scale globally. And it highlights the gap between technical possibility and operational discipline.
We often think of cybersecurity in terms of endpoints and applications. But sometimes the most consequential vulnerabilities sit below everything — invisible to users, rarely discussed outside networking circles.
The internet routes billions of packets per second.
And in some cases, it does so based on trust alone.