Solana was 4.51 points from losing the ability to finalize transactions on the morning of Wednesday (12), after a routing failure at hosting provider Teraswitch took 28.83% of the network's staked SOL offline, according to data released by Marinade Finance.
The network halts finalization when 33.34% of staked SOL is not participating. With 28.83%, it was about 86% of the way to a halt. Teraswitch published a report explaining the incident.
According to the provider, a default route from the Miami site was propagated without metrics and communities, and a route reflector in Amsterdam pushed it toward Europe and Asia-Pacific. Edge routers interpreted it as local and forwarded it to the data center core, which rejected it. Twelve sites in London, Amsterdam, Dublin, Frankfurt, Singapore and Tokyo were left without valid routes. North America was not affected. Engineers identified the failure within ten minutes and service returned at 04:16 UTC.
Stake concentration
Marinade Finance, which analyzed the numbers afterward, found that the outage was concentrated in a single autonomous system, AS20326, which carries 118,890,767 SOL — more than a quarter of all network stake. Of that total, 94% went offline at the same time. The system operates above the 25% per-autonomous-system cap set by the Solana Foundation's delegation program: it is at 27.34%.
The analysis also showed that 59 validators with 80.2 million SOL came back in the same window in Amsterdam, Frankfurt and Tokyo, after waiting for route reconvergence. Helius, Solana's second-largest validator, was offline during those 33 minutes. Among 74 operators measured, three came back without issues: Laine and Cogent Crypto, both operated by Sol Strategies, and Lion3d.
Another 14.1 million SOL went offline in the same minutes at latitude.sh, Limestone, Butterfly Research and Allnodes, something Marinade said it could not explain from the data and that indicates measuring stake by provider underestimates correlated failures.
Marinade itself acknowledged concentration in its allocation: four autonomous systems concentrate two-thirds of the stake distributed by its model, and one of them, AS395201, accounts for 36.94%. "Nobody should feel comfortable with this, including us," the company said, adding that it will review concentration limits by network and data center and will begin publishing whether a validator uses hot swap and automatic failover.
The 333 SOL lost in rewards will be covered by validator guarantees at the end of the epoch. If the failure had exceeded one-third, nothing would have been finalized for any SOL holder, and no guarantee would cover that. In Solana's last full halt, in February 2024, the network took nearly five hours to restart.
