One design principle of modern network architecture seems to be set in stone: a software-based control plane drives a hardware- or software-based data plane. We argue that it is time to revisit this principle after the advent of programmable switch ASICs which can run complex logic at line rate. We explore the possibility and benefits of accelerating the control plane by offloading some of its tasks directly to the network hardware. We show that programmable data planes are indeed powerful enough to run key control plane tasks including: failure detection and notification, connectivity retrieval, and even policy-based routing protocols. We implement in P4 a prototype of such a “hardware-accelerated” control plane, and illustrate its benefits in a case study. Despite such benefits, we acknowledge that offloading tasks to hardware is not a silver bullet. We discuss its tradeoffs and limitations, and outline future research directions towards hardware-software codesign of network control planes.

Passive measurement is a commonly used approach for measuring round trip time (RTT), as it reduces bandwidth overhead compared to large-scale active measurements. However, passive RTT measurement is limited to transport-specific approaches, such as those that utilize Transmission Control Protocol (TCP) timestamps. Furthermore, the continuing deployment of encrypted transport protocols such as QUIC hides the information used for passive RTT measurement from the network. In this work, we introduce the latency spin signal as a light-weight, transport-independent and explicit replacement for TCP timestamps for passive latency measurement. This signal supports per-flow, single-point and single direction passive measurement of end-to-end RTT using just three bits in the transport protocol header, leveraging the existing dynamics of the vast majority of Internet-deployed transports. We show how the signal applies to measurement of both TCP and to QUIC through implementation of the signal in endpoint transport stacks. We also provide a high-performance measurement implementation for the signal using the Vector Packet Processing (VPP) framework. Evaluation on emulated networks and in an Internet testbed demonstrate the viability of the signal, and show that it is resistant to even large amounts of loss or reordering on the measured path.

Simple path tracing tools such as traceroute allow malicious users to infer network topologies remotely and use that knowledge to craft advanced denial-of-service (DoS) attacks such as Link-Flooding Attacks (LFAs). Yet, despite the risk, most network operators still allow path tracing as it is an essential network debugging tool. In this paper, we present NetHide, a network topology obfuscation framework that mitigates LFAs while preserving the practicality of path tracing tools. The key idea behind NetHide is to formulate network obfuscation as a multi-objective optimization problem that allows for a flexible tradeoff between security (encoded as hard constraints) and usability (encoded as soft constraints). While solving this problem exactly is hard, we show that NetHide can obfuscate topologies at scale by only considering a subset of the candidate solutions and without reducing obfuscation quality. In practice, NetHide obfuscates the topology by intercepting and modifying path tracing probes directly in the data plane. We show that this process can be done at line-rate, in a stateless fashion, by leveraging the latest generation of programmable network devices. We fully implemented NetHide and evaluated it on realistic topologies. Our results show that NetHide is able to obfuscate large topologies (> 150 nodes) while preserving near-perfect debugging capabilities. In particular, we show that operators can still precisely trace back > 90% of link failures despite obfuscation.