The northern Cyprus ISP Multimax (AS197792) employed IP-based blocking rather than DNS hijacking, and its blocked-site list — including Wikipedia, Tor Project, Wikileaks, and Psiphon — matched Turkish ISP blocklists rather than the RoC NBA gambling blocklist, demonstrating that geopolitically distinct ISP operators on the same island implement categorically different censorship regimes.

All five Republic of Cyprus ISPs (Callsat AS24672, Cablenet AS35432, Cyta AS6866, MTN AS15805, and Primetel) used DNS hijacking as their sole blocking mechanism, creating local zone entries that override legitimate DNS replies and redirect users to ISP-controlled block pages or error pages.

§6 detection

The Republic of Cyprus National Betting Authority (NBA) blocklist grew from 95 URL entries in February 2013 to 2,563 entries in April 2017 — approximately 27 times its initial size — with entries specifying full URL paths rather than just domain names, requiring DPI-capable infrastructure for correct enforcement.

§4.1 evaluation

DNS hijacking used by Cypriot ISPs to block gambling websites also suppressed MX record responses for blocked domains, rendering email delivery to those domains impossible — collateral damage not mandated by the 2012 gambling law, which required only URL blocking.

§6.7 evaluation

Cypriot ISPs could not enforce HTTPS URL entries from the NBA blocklist because SSL/TLS interception was not deployed; connections to port 443 for blocked domains simply timed out with no block page or user notification, meaning HTTPS entries were effectively under-blocked.

§4.1 detection

The June 2025 Iran shutdown—carried out during the Iran-Israel war beginning ~June 19—did not use BGP route withdrawals as in 2019. Instead, authorities applied service-level restrictions at the national border: DNS poisoning of foreign destinations, protocol whitelisting permitting only pre-approved domestic services, and DPI to block circumvention-tool traffic. Iran's international traffic fell roughly 90% while the country's BGP routes remained advertised, making the shutdown invisible to BGP-based monitoring systems. OONI measurement volume, which totalled 121,333 in June 2025, collapsed to under 200 submissions on June 19-20.

2025-iran-shutdown-measurement Executive Summary / §2 dpidns-poisoningport-blockingip-blocking

Chinese users treat full proxy/VPN (Shadowsocks, V2Ray/Clash, commercial VPNs) as the '终极大杀器' (ultimate solution) for bypassing GitHub DNS poisoning, implying that lighter-weight DNS-only fixes fail in some network environments where the censor adds firewall-layer blocking beyond DNS.

2026-anon-6-github-dns §3 使用代理或 VPN dns-poisoningip-blocking

Rule-based proxy tools (Clash, Shadowsocks, V2Ray) are documented as the most reliable solution for accessing GitHub from China, with split-tunneling rules routing only GitHub traffic through the proxy while keeping domestic traffic on the direct path. Git command-line tools require explicit proxy configuration (git config --global http.proxy http://127.0.0.1:7890) to route clone/push operations, as they do not inherit system proxy settings automatically.

2026-anon-github-2026-6-dns §方法二 dns-poisoningip-blocking

The GFW blocks GitHub via DNS poisoning across at least four domains — github.com, assets-cdn.github.com, github.global.ssl.fastly.net, and raw.githubusercontent.com — causing connection timeouts and page-load failures for mainland China users. The block is persistent as of February 2026, affecting both browser access and command-line git operations.

2026-anon-github-2026-6-dns Introduction / §方法一 dns-poisoningip-blocking

Article 19 documents that Iran's National Information Network (NIN / SHOMA) was designed with explicit reference to China's Great Firewall as a model, with institutional mirroring: Iran's Supreme Council of Cyberspace parallels China's Cyberspace Administration of China, and both governments share a "cyber sovereignty" doctrine used to justify domestic content controls and cross-border technology transfer. The report frames Iran's filtering infrastructure as deliberately architected to replicate GFW capabilities, not as an independently developed system.

2026-article19-tightening-the-net §2, §3 dpisni-blockingdns-poisoningip-blockingbgp-hijackthrottling

Article 19 documents that Iran combines technical filtering with formal coercion of major foreign platforms (including Telegram, Instagram, and WhatsApp) to comply with content removal orders under threat of full blocking. The report notes that Iran's 2022 Women Life Freedom protests accelerated platform blocking when foreign operators refused compliance, demonstrating that the censorship system operates in two modes: coerce-and-allow for compliant platforms, block for non-compliant ones. Domain fronting via these platforms is therefore subject to sudden revocation if political conditions change.

2026-article19-tightening-the-net §6 ip-blockingdns-poisoningthrottling