October 2025 · Estimated read time: 15 minutes
Interdomain Routing Reimagined: Future-Proofing the Internet Core
Interdomain routing—the backbone of how autonomous systems exchange reachability information—continues to rely on protocols and paradigms defined decades ago. The Border Gateway Protocol (BGP), introduced in the late 1980s, remains the de facto standard, despite fundamental limitations in security, convergence, and scalability. As the modern internet evolves into a more complex, performance-sensitive, and security-conscious fabric, the case for reimagining interdomain routing grows stronger.
The Limitations of BGP as We Know It
BGP’s original design prioritizes reachability and policy enforcement but leaves several critical aspects to chance or indirect mechanisms. It assumes trust among peers, lacks cryptographic integrity, and operates with slow, often unpredictable convergence. More importantly, BGP lacks native support for traffic engineering across domains, QoS guarantees, or end-to-end security verification.
These weaknesses manifest in high-profile route leaks, hijacks, and instability events—many of which are preventable. Efforts like BGPsec and RPKI aim to address specific issues, but they add complexity and require global coordination for limited incremental benefit.
Modern Demands Require More
The modern internet environment is unrecognizable from that of the 1990s. Multi-cloud architectures, edge computing, satellite internet constellations, and zero-trust networking models demand greater control, visibility, and predictability in routing behavior. Traditional BGP offers none of these.
Network operators need mechanisms to express intent, control routing based on performance characteristics, and verify path integrity across autonomous systems. Emerging application requirements—like ultra-low latency AR/VR or high-throughput inter-datacenter transfers—cannot tolerate BGP’s slow convergence or policy-induced black holes.
Key Concepts for a Modern Interdomain Model
A future-ready interdomain routing architecture would not just bolt improvements onto BGP, but replace or augment it with a new model. Some of the foundational ideas that are gaining traction include:
- Cryptographic Path Validation: Every AS hop should be verifiable, akin to how DNSSEC provides assurance of record integrity.
- Performance-Aware Routing: ASes should share performance metrics (latency, jitter, packet loss) in a verifiable way for SLA enforcement or QoS-driven path selection.
- Policy Abstraction: Instead of relying on vendor-specific policy expressions, a common high-level policy language could simplify interdomain agreements and automation.
- Path Constraints and Intent: Support for expressing required and forbidden AS paths, preferred peering zones, or jurisdiction-aware routes could enhance compliance and trust.
- Programmability and API Exposure: Exposing interdomain routing control planes via secure APIs would support automated operations and intent-based networking at scale.
Lessons from Inside the Data Center
Inside large data centers, traditional routing protocols have already been replaced by more modern control planes. Spine-leaf architectures, overlay networks, and SDN controllers use programmatic policy, distributed state, and telemetry to achieve high performance and rapid failover. These principles can inform interdomain routing evolution.
For example, instead of exchanging full routing tables, ASes could exchange signed summaries of path viability or subscribe to intent-based overlays. In the same way BGP communities provide tagging hints today, future protocols might carry contractually enforced SLA tags or telemetry-driven hints.
Challenges in Moving Beyond BGP
The transition from BGP to a modern control plane involves monumental technical and political challenges. BGP is deeply entrenched in routers, policies, and processes worldwide. Any replacement must interoperate gracefully, provide incentives for early adopters, and offer tangible benefits.
Incremental adoption strategies are key. One approach is encapsulating next-gen routing data inside existing BGP mechanisms (like using BGP-LS or new SAFIs). Another is using overlays—such as segment routing with interdomain controllers—to add functionality without disrupting the BGP core.
Global cooperation is also critical. Standards bodies, operators, vendors, and governments must align on trust models, identity mechanisms, and interoperability. Projects like MANRS, SCION, and RPKI show that progress is possible when the right incentives and threat models are clearly defined.
Opportunities from SD-WAN and SASE
The rapid adoption of SD-WAN and Secure Access Service Edge (SASE) provides an opportunity to pilot new interdomain control mechanisms. These technologies already abstract routing behavior across multiple providers and prioritize application awareness.
By federating SD-WAN control planes and integrating them with cloud-based secure routing exchanges, operators could test performance-aware routing across providers. Lessons from such experiments could inform larger standards efforts and accelerate adoption.
The Path Ahead
Reimagining interdomain routing is not just about fixing BGP—it’s about building a routing architecture that aligns with modern realities and future needs. This architecture must be secure, programmable, performance-sensitive, and policy-rich.
Key steps in this journey include:
- Encouraging community participation in evolving standards (IETF, MANRS, RPKI, SCION).
- Funding academic and open-source research into programmable routing control planes.
- Supporting inter-AS collaboration in SD-WAN, SASE, and IX federation.
- Implementing security-first primitives like signed path assertions and path constraints.
- Aligning regulatory, privacy, and operational models across regions.
As traffic demands increase, attack surfaces widen, and critical services move to the cloud, the need for a modern interdomain routing foundation becomes urgent. By taking proactive steps today, we can build an internet core that is robust, secure, and ready for the next decade of innovation.
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