Insights from Block Propagation in the Ethereum P2P Network
Mikel Cortes
About this talk
Mikel Cortes presents ProbeLab's analysis of block propagation in Ethereum's consensus layer, which relies on the GossipSub libp2p protocol to disseminate validator duties across the network. He explains how external factors such as MEV-driven proposer timing games, block size, and network topology shape propagation latency, and shows measurement results indicating that 55% of blocks arrive with at least three duplicates and that some edge cases see the same message up to eight times. The talk introduces Hermes, an open-source libp2p-based event tracer that connects to Ethereum nodes to stream internal GossipSub events, and a public dashboard built in collaboration with the Ethereum Foundation and EthPandaOps that visualizes block arrival times at sentry nodes. Cortes argues that continuous monitoring is essential for anticipating regressions across client releases and for guiding scaling work toward PeerDAS and FullDAS.