2022-oftenhamed-vless-tls-has

Vless + TLS has a weird behavior on Iran VPS

@oftenhamed, @surbiks, @poorp, @aliafshany · net4people/bbs · 2022

Abstract

Iranian user reports selective service blocking when using VLESS+TLS from a domestic VPS: Telegram (IP-based) remains accessible while Instagram, YouTube, and Facebook are blocked or partially inaccessible. Community analysis identifies DNS poisoning disrupting domain-based resolution and IP-list blocking of media CDNs as root causes; client-side DNS configuration in V2rayNG provides a workaround.

Team notes

Auto-ingested via corpus-crawl. Tags proposed by Claude Haiku 4.5; review and tighten before relying. Primary-source evidence of Iran's DNS disruption limiting VLESS+TLS effectiveness against multi-layer censorship.

Tags

censors: ir
techniques: dns-poisoning ip-blocking
defenses: vless

findings extracted from this paper

Iran's censorship infrastructure employs IP-list blocking of major media CDNs (Instagram, YouTube, Facebook) that remains effective against VLESS+TLS users on domestic VPS endpoints. Telegram's accessibility—because it is reachable directly by IP without domain resolution—confirms that the IP blocklist targets CDN address ranges specifically rather than applying blanket traffic inspection.

Issue thread (abstract) detection ip-blocking ir
Community analysis of the Iran VLESS+TLS failure identified DNS poisoning as a primary root cause: domain-based resolution for services like Instagram, YouTube, and Facebook was disrupted even when traffic transited a VLESS+TLS tunnel from a domestic VPS, bypassing the transport-layer obfuscation entirely.

Issue thread (abstract) detection dns-poisoning ir
This primary-source community report documents that Iran's censorship is multi-layered: VLESS+TLS successfully evades transport-protocol detection but is defeated simultaneously by DNS poisoning and CDN IP-list blocking. A circumvention tool that addresses only one layer (transport obfuscation) is insufficient for consistent access in Iran.

Issue thread (abstract) evaluation dns-poisoningip-blocking ir
Iran's censorship against VLESS+TLS users on domestic VPS infrastructure is selective by destination type: Telegram, which is accessed by IP, remained reachable, while Instagram, YouTube, and Facebook were blocked or partially inaccessible. This indicates blocking operates at the destination-IP/domain layer independently of the transport protocol.

Issue thread (abstract) detection ip-blockingdns-poisoning ir
Configuring client-side DNS settings within V2rayNG resolves the DNS poisoning component of Iran's multi-layer censorship when using VLESS+TLS from a domestic VPS. This workaround routes DNS queries through the tunnel rather than the local, poisoned resolver, restoring domain resolution for blocked services.

Issue thread (abstract) defense dns-poisoning ir