China has only 3 points of control covering approximately 240 million IP addresses (roughly 80 million IPs per point of control), the lowest ratio among large-population countries. This enabled China to cut off nearly all Internet access for the Xinjiang region for ten months beginning July 2009.

Russia's high AS complexity (score 19.39, 2,346 ASes) enabled the Russian Business Network to hide malware-hosting ASes by chaining traffic through multiple intermediate legitimate-seeming ASes, making connections very difficult to trace and sever. The paper concludes that higher national AS complexity directly raises the operational cost of enumerating and cutting any given connection.

§IV, §VI defense

Eastern Asia averages 4.80 points of control and a complexity score of 1.54 across 510 million IP addresses, while Eastern Europe averages 19.10 PoC and a complexity score of 11.35 across 74 million IPs — nearly twice the complexity of any other region. Russia specifically has 2,346 autonomous systems and a complexity score of 19.39, versus China's 177 ASes and score of 0.11.

§II, Table II, Table III evaluation

By 2009, the top 150 autonomous systems carried approximately 50% of all Internet traffic globally, up from roughly 30% in 2007. Akamai alone claimed approximately 20% of all web traffic, and the proposed Level 3 / Global Crossing merger would have covered over half the world's IP addresses.

§I evaluation

Iran and Libya each have a single point of control (1 AS), making complete national internet shutdown achievable with a single administrative action. Egypt's 2011 shutdown left one AS (Noor Group, 4.9% of connected IPs) operational for four days, apparently due to its role serving the Egyptian stock exchange and other core financial institutions.

§VI, Figure 7 deployment

Brussee measures a systematic pattern of Chinese government websites actively blocking access from outside China (the "reverse Great Firewall"), publishing a CSV dataset of affected domains (available at zenodo.org/records/18172145). The paper frames this outbound geo-blocking as a cybersecurity-motivated practice — Chinese authorities classify foreign access to domestic government infrastructure as an attack surface — distinct from the inbound information control goal of the GFW.

2026-brussee-reverse-great-firewall §3, §5 ip-blockingasn-blackholing

Brussee develops a conceptual framework distinguishing two logics of government geo-blocking: (1) information control (blocking inbound foreign content from domestic users) and (2) data sovereignty / attack-surface reduction (blocking outbound access by foreign actors to domestic systems). Chinese government site blocking of external IPs is motivated primarily by the second logic, creating an asymmetric internet topology where CN citizens cannot reach the outside world, and outside actors cannot probe CN government infrastructure.

2026-brussee-reverse-great-firewall §2, §4 ip-blockingasn-blackholing

NetShuffle targets edge networks — small autonomous systems and entities that obtain IP address blocks from upstream providers — as a new class of support base for circumvention infrastructure. This class has received scant attention from prior work, which has focused on cloud providers and volunteer desktop machines. Edge networks represent a large pool of diverse IP space that is harder to block via ASN blackholing compared to a small number of major cloud providers.

2024-kon-netshuffle §1, §2 ip-blockingasn-blackholing

Documented Internet shutdown events grew from 75 in 2016 to 213 in 2019 across 33 countries, with individual shutdowns lasting from hours to 472 days (Chad). These shutdowns completely sever IP connectivity, rendering all existing circumvention tools (Tor, VPNs, Shadowsocks, etc.) non-functional since they require at least partial Internet access to operate.

2023-sharma-dolphin §1–2 asn-blackholingip-blocking

27 of 80 tested VPN providers had servers within a single AS (AS 9009, M247 Ltd), and VPNalyzer identified 14 providers sharing 4 specific IP blocks within that AS; 2 additional providers shared an IP block in AS 60068 (Datacamp). Such infrastructure concentration enables censors to block multiple VPN products simultaneously with a single IP-range or AS-level rule.

2022-ramesh-vpnalyzer §VI-D ip-blockingasn-blackholing

Seven years of Roskomnadzor blocklist history (Nov 2012–April 2019) show the list grew to 132,798 unique domains and 324,695 unique IPs, with a dramatic spike in 2018 when Russia blocked Telegram by adding subnets covering approximately 16 million IP addresses—producing major collateral damage to co-hosted Google and Amazon services and illustrating that subnet-level blocking is the blunt instrument of last resort for CDN-hosted targets.

2020-ramesh-decentralized §VI-A, §II-B ip-blockingasn-blackholing