  In Ethereum, the ledger exchanges messages along an underlying Peer-to-Peer
(P2P) network to reach consistency. Understanding the underlying network
topology of Ethereum is crucial for network optimization, security and
scalability. However, the accurate discovery of Ethereum network topology is
non-trivial due to its deliberately designed security mechanism. Consequently,
existing measuring schemes cannot accurately infer the Ethereum network
topology with a low cost. To address this challenge, we propose the Distributed
Ethereum Network Analyzer (DEthna) tool, which can accurately and efficiently
measure the Ethereum network topology. In DEthna, a novel parallel measurement
model is proposed that can generate marked transactions to infer link
connections based on the transaction replacement and propagation mechanism in
Ethereum. Moreover, a workload offloading scheme is designed so that DEthna can
be deployed on multiple distributed probing nodes so as to measure a
large-scale Ethereum network at a low cost. We run DEthna on Goerli (the most
popular Ethereum test network) to evaluate its capability in discovering
network topology. The experimental results demonstrate that DEthna
significantly outperforms the state-of-the-art baselines. Based on DEthna, we
further analyze characteristics of the Ethereum network revealing that there
exist more than 50% low-degree Ethereum nodes that weaken the network
robustness.
