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The RealValidator Team Editorial team

An Autonomous System Number (ASN) is the globally unique integer that identifies the hosting network (typically a datacenter operator, cloud provider, or ISP) routing a Solana validator's traffic, and it is the primary signal used by the Solana ecosystem to measure infrastructure concentration risk. Stakers and stake-pool selection algorithms penalize validators whose ASN already hosts a large share of network stake, because a fault in that single ASN — a power event, a routing issue, a coordinated takedown — would simultaneously affect every validator behind it.

Each validator's identity is associated with a public IP address that resolves to an ASN via the global Border Gateway Protocol routing table. Validators.app and Stakewiz both publish the ASN for each validator on their profile records; the data is observable rather than self-reported.

Why concentration matters for stakers

Solana's security and liveness depend on stake being distributed across uncorrelated failure domains. If a single ASN hosts 30% of staked SOL, a single network event in that ASN can cause 30% of the network's vote producers to go offline simultaneously, which crosses thresholds that affect liveness and can interrupt block production until the affected validators recover. The risk is not theoretical: cloud outages, BGP misconfigurations, and ISP-level events have produced multi-hour disruptions affecting all customers of a given network.

The SFDP codifies this concern with explicit thresholds. As of May 1, 2026, SFDP-participating validators may not be hosted on an ASN that carries more than 25% of network stake, and the data center concentration cap is 15% (per solana.org/delegation-criteria). Validators crossing these caps lose SFDP eligibility until they migrate to a less-concentrated network.

Stake pool selection algorithms apply similar penalties. Marinade's SAM and the Jito Stake Pool each weight ASN concentration as a negative factor; the Wiz Score applies an ASN-concentration penalty as part of its decentralization component.

TeraSwitch AS20326 — current real flag

TeraSwitch (AS20326) is the most concentrated ASN on the Solana network at epoch 971. Approximately 29% of total staked SOL is hosted within AS20326 (per Validators.app ASN tracker, May 2026), exceeding the SFDP 25% threshold that takes effect May 1, 2026. Four of the 28 validators profiled in this wiki are on AS20326, including high-stake operators (Helius, Jito Labs, Jupiter, Bitwise).

The practical staker takeaway: a 29% ASN concentration is a real flag, not a hypothetical concern. A staker delegating to a TeraSwitch-hosted validator is increasing their exposure to a single ASN that already exceeds the Foundation's tolerable concentration threshold. Stakers concerned about decentralization should check the ASN field on a validator's profile before delegating, and prefer validators on ASNs holding a smaller share of network stake.

How to read the ASN field

Validators.app and Stakewiz both expose the ASN on validator records (e.g. AS20326 for TeraSwitch, AS24940 for Hetzner, AS16276 for OVHcloud). The number alone identifies the network; the readable name is informational. When comparing validators by decentralization, the meaningful number is the ASN's network-stake share, not the validator's individual stake — Validators.app publishes a network-stake-by-ASN table updated each epoch.

ASN vs data center vs city vs country

ASN concentration is the most specific decentralization signal. Below it sit data center concentration (multiple ASNs can share a data center; multiple validators in the same data center share physical-layer failure modes) and city / country concentration (geographic concentration affects regulatory and natural-disaster failure correlation). SFDP enforces caps at the ASN and data center levels; Marinade SAM and Wiz Score weight all four. A validator can pass the ASN cap and fail the data-center cap if multiple ASNs in the same building both host stake.

Terminology traps

  • "ASN" is not "hosting provider." Many providers operate multiple ASNs; some ASNs span multiple physical locations. The ASN is the routing identifier specifically.
  • "AS20326" and "TeraSwitch AS20326" are the same thing. The "AS" prefix is the standard notation; the name is the operator's brand for that network.
  • An ASN's concentration is a network-level property, not the validator's fault. A validator can be perfectly run and still contribute to ASN concentration risk simply by sharing an ASN with many other operators. The penalty is structural, not punitive.
  • ASN can change. A validator that migrates to a new provider acquires a new ASN at the cutover; previous ASN history is observable in Validators.app's commission/ASN change log.

Sources

ASN concentration figures cited reference Validators.app cluster data at epoch 971, 2026-05-15. ASN shares shift each epoch as validators migrate and stake redistributes; verify on a fresh snapshot when citing for current decisions.