A community scan of the I2P network database (netDb) in July 2026 identified a cluster of suspicious router nodes uniformly running I2P version 0.9.66 (three versions behind the current 0.9.69), all hosted in Chinese domestic data centers rather than residential broadband. The nodes exhibit anomalous uniformity in their router capabilities (Caps) configuration and self-reported versions, a pattern inconsistent with organic user deployments.

The suspected Chinese surveillance nodes are hosted in data centers that explicitly prohibit 'circumvention services' (proxy/VPN services) in their terms of service, yet the nodes operate safely for extended periods. This suggests the operators benefit from either state-sanctioned access or ISP-level protection from ToS enforcement, consistent with a government or contractor intelligence-collection operation.

Issue body deployment

The suspicious Chinese I2P nodes rotate their IP addresses regularly and simultaneously as a coordinated group, and some of the observed IPs have prior history of malicious behavior (SSH brute-forcing, remote exploitation) in threat-intelligence databases. Simultaneous coordinated IP rotation distinguishes state-run infrastructure from organic users and is a fingerprint of centrally managed probe fleets.

Issue body detection

The author released a netDb scanner tool that reads the local I2Pd network database, identifies routers hosted on Chinese IP ranges, and exports results as IP lists for firewall rules. The tool supports filtering by country (--cn-only), JSON export, and IP-list export, enabling operators to block suspected surveillance nodes at the OS firewall layer before any I2P connection is made.

Issue body — scanner download defense

CensorLess's function refresher automatically retires serverless bridges and deploys fresh ones in batches across diverse regions; the expected time until a bridge is identified and blocked in practice is 2 days (per Fifield et al.), while Tor bridges in China are discovered within 2–36 days. The old bridge is only removed after all clients have completed live migration to a new URL, maintaining uninterrupted connectivity.

2026-kang-censorless-serverless §4.5 active-probingip-blocking

CensorLess's threat model explicitly relies on a rational-censor assumption: the censor will not block entire cloud-provider IP ranges or domain namespaces because the collateral damage to legitimate business services would be politically and economically unacceptable. AWS Lambda's inherent IP-address ephemerality (new IPs on each invocation, function lifetime up to 15 minutes) means even censors willing to attempt enumeration face a continuously shifting target distributed across the cloud provider's global address space.

2026-kang-censorless-serverless §4.2 ip-blockingasn-blackholingactive-probing

Address blocking is a losing strategy for the censor: with n=8 endpoints and µ/λa = 1 (discovery as fast as rotation), address-denial probability falls below 10^-2, and even when the censor discovers twice as fast as the defender rotates (µ/λa = 0.5), 7 endpoints keep address denial below 10^-2 (Lemma 1, Figure 1). The collateral budget γ means the censor cannot even block all addresses it discovers, and Corollary 1 gives the explicit threshold: n ≥ ln(1/ε) / ln((λa+µ)/λa) endpoints suffice for any target ε.

2026-maiti-block-a-mole-sustainability-frontier §5, §8.1, §8.10, Lemma 1, Corollary 1, Figure 1 ip-blockingactive-probing

Community members propose a two-hop architecture as a potential mitigation for Iran's current DPI upgrade: a first-hop server inside Iran's whitelisted datacenter ranges (where outbound traffic faces lighter inspection) proxying to a foreign exit node, with Reality masquerading as a legitimate Iranian organization's domain. The architecture's effectiveness under active TCP reassembly and handshake probing is explicitly unverified.

2026-pooribitwise-iran-advanced-dpi Issue body — Description active-probingip-blocking

Active scanning of bridges for censorship verification must be minimized because each scan independently risks exposing the scanning infrastructure to the censor, with discovery probability modeled as a monotonically increasing function of scan volume. Troll Patrol reduces required scans by limiting active verification to only bridges for which user-submitted negative reports have been received, and revokes reporting privileges from users who accumulate too many false reports to deter scan-flooding attacks.

2026-vecna-troll-patrol-anonymous §2.2, §7 active-probingip-blocking

Obscura proxies resist active probing by never exposing open ports or accepting incoming connections; combined with a large ephemeral volunteer pool (analogous to Snowflake's scale), the vast IP address space and rapid proxy rotation make exhaustive enumeration infeasible without causing sufficient collateral damage to deter the censor — consistent with the absence of observed blind-blocking campaigns against Snowflake.

2026-vilalonga-obscura-enabling-ephemeral §5.1 active-probingip-blocking