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V2Ray Glossary

From subscriptions and servers to TUN and routing, understand the concepts before changing settings. Each entry explains what a term does, when it is used, and what it should not be confused with.

Configuration layers at a glance

The client provides the interface; the core handles connections. Protocols define communication, transports carry data, proxy modes intercept traffic, and routing rules select the outbound route. These terms describe different layers and are not interchangeable.

Client
Subscription
Proxy mode
Routing rules

Protocols and transport

Check the protocol, security layer, and transport separately. Matching names do not mean the other settings match.

VMessProxy protocol: VMess is a proxy protocol in the Project V ecosystem. It authenticates connections using parameters such as a user ID and includes its own data protection mechanism. The client address, port, user ID, and security options must match the server. VMess supports different transports, so confirming the protocol name alone does not rule out issues with the path, TLS, or system time.

VLESSProxy protocol: VLESS is a lightweight proxy protocol that does not provide VMess-like payload encryption; deployments commonly use it with TLS or REALITY. After importing a configuration, check the user ID, transport, security layer, and any flow required by the server. VLESS and VMess are not interchangeable: changing only the protocol type in the editor while keeping the other settings is not sufficient.

TrojanProxy protocol: Trojan typically protects connections with TLS and authenticates using a password. The server address, port, password, and server name can all affect the connection; the server name also matters for certificate validation. If the password is correct but the TLS handshake fails, check the certificate, system time, and server name instead of repeatedly changing the password.

TLSTransport security: TLS protects data in transit and verifies the server's identity using mechanisms such as certificates. It is neither a subscription format nor a standalone proxy protocol. Client settings such as server name, certificate validation, and ALPN belong to this layer. For certificate errors, check the name, validity period, and system trust chain first; disabling certificate verification is not a recommended long-term fix.

REALITYTransport security: REALITY is a transport security mechanism in the Xray ecosystem, often used with VLESS. The client must match the server's public key, server name, shortId, and other parameters; available fields depend on the configuration format and core support. REALITY is neither a server location nor a routing mode. If an import fails, check whether the client can parse these fields correctly.

TransportData transport: Transport describes how proxy protocol data is carried and transmitted; common options include TCP, WebSocket, and gRPC. It is a separate layer from protocols such as VMess and VLESS. Some combinations also require a path, Host value, or service name. If the server port is reachable but proxy requests fail, check these additional parameters.

Cores and clients

The interface manages settings; the core executes connections. Learn what project names mean to avoid confusing ecosystems, apps, and connection capabilities.

Project VEcosystem: Project V is the open-source proxy project and ecosystem built around components such as V2Ray, not the name of a graphical client. A “V2Ray client” usually means an app with a user interface, while the underlying core handles connections. To determine whether a feature is available, check client support and the core actually in use rather than relying on the ecosystem name alone.

V2FlyCore project: V2Fly is the community project that continues to maintain the V2Ray core, which handles connections, protocol parsing, routing, and DNS. v2flyNG is an Android client based on this core ecosystem. Features and configuration details can vary across cores, so a configuration that works with one core may not work unchanged with another.

XrayCore project: Xray is a proxy core project that grew out of the V2Ray technology ecosystem, with its own features and evolving configuration. v2rayNG uses the Xray core; the desktop v2rayN client's connection capabilities depend on the selected core. If a configuration field is unrecognized or a feature is unavailable, check the core type and runtime logs rather than judging by the client interface alone.

Graphical clientUser interface: A graphical client provides an interface for managing subscriptions, choosing servers, setting proxy modes, and viewing logs. v2rayN, v2rayNG, and v2flyNG all belong to this layer. The client creates or manages configurations, while the core handles connections, so consider their updates and compatibility separately. A client is not a subscription service; you still need to import a usable configuration after installation.

Subscriptions and servers

A subscription is a source of configurations, a server is a connection option, and a group is an organizational tool. A successful update does not mean a successful connection.

SubscriptionConfiguration source: A subscription is a resource maintained by a service provider that lets clients retrieve a set of server configurations, usually by importing a URL. Subscription URLs may contain personal access credentials; do not share them in public screenshots, chat logs, or support requests. Updating a subscription refreshes the configuration list; it does not mean the service is still active or that the system proxy or TUN is enabled.

ServerServer configuration: A server usually means a connection profile that a client can select, containing an address, port, authentication details, protocol, and transport settings. Region or route names in the list are labels, not proof of the actual exit location or connection quality. One server may have multiple profiles, so the number of entries does not necessarily equal the number of distinct servers.

Subscription groupList management: A subscription group is a client-side unit for organizing subscriptions and servers by source. Different sources can have their own labels, update options, and filters. Groups help identify expired entries and duplicate names, but usually do not determine where traffic is routed. When organizing a list, confirm the source before changing filters so an empty filtered list is not mistaken for an expired subscription.

Latency and TCPingConnectivity metrics: Latency is the time taken by a particular test, so check the test method before interpreting the result. TCPing typically measures the time needed to establish a TCP connection to a target port; it does not fully test proxy authentication, TLS, transport settings, or website access. A low value does not mean faster downloads. When choosing a server, also consider proxy connection latency and real-world access to the services you use.

Routing and split routing

First check whether traffic reaches the core, then see which route the rules select. Domain and IP rules apply to different kinds of traffic.

Routing ruleOutbound route selection: Routing rules direct connections to routes such as direct, proxy, or blocked based on domains, IPs, ports, or other conditions. Most common configurations check rules in order, so a broad rule placed too early can prevent a more specific rule from taking effect. Troubleshooting requires checking rule order, match conditions, and the default route—not just confirming that a rule exists.

Split routingTraffic policy: Split routing sends traffic for different destinations through different routes—for example, sending local services direct and routing specified domains through a proxy. “Bypass mainland China” and “Global” are common client presets; their actual scope depends on the rules, default route, and how traffic is intercepted. Global routing cannot automatically handle traffic from apps that never reaches the client.

GeoIPIP address set: GeoIP is a collection of IP addresses grouped by region or purpose, often used in rules with identifiers such as geoip:cn. It matches IP addresses, not domain strings, and does not measure a server's location in real time. Dataset updates, resolved domain addresses, and CDN routing can all affect results, so a match does not confirm a service's physical location.

GeoSiteDomain set: GeoSite is a collection of domains grouped by service, region, or category, often used for matching with identifiers such as geosite:cn. It depends on the labels and coverage in the selected data source; categories with the same name should be interpreted using the actual data file. Unlike GeoIP, GeoSite requires domain information to match. A domain rule may not match when only the destination IP is available.

DNSDomain name resolution: DNS resolves domain names to records such as IP addresses and is a prerequisite for accessing websites and some IP-based routing decisions. Apps, the operating system, and the proxy core may each perform their own lookups, and a browser's encrypted DNS settings can change the resolution path. Check which resolver is queried, which route DNS requests take, and how returned addresses are used for routing; entering a DNS server address alone does not complete the configuration.

Proxy modes and networking

System proxy and TUN determine how traffic is intercepted; DNS affects the resolution path, and connection tests help verify the result.

System proxyApp connectivity: The system proxy registers a local proxy address with the operating system so apps that honor the setting can send requests through the client. Some apps use their own network settings or ignore the system proxy, so a working browser does not mean every program is using the proxy. Clear settings that point to a stopped local port before closing the client, or apps may keep trying to connect to it.

TUN modeTraffic interception: TUN mode uses a virtual network interface to intercept IP-layer traffic and pass it to the proxy core, making it useful when more app traffic needs to be covered. It typically involves additional permissions, system routes, and DNS settings; requirements vary by platform and client implementation. Enabling TUN does not mean all traffic goes through the proxy—routing rules still select the outbound route. If problems arise, check for conflicts with other networking tools.

FakeDNSDomain mapping: FakeDNS assigns virtual addresses to domains, then lets the core map incoming connections back to those domains so their names remain available for further processing. It is not a public DNS server address to enter in any app. Whether it works depends on core support and traffic interception settings. If apps have trouble accessing sites after enabling or disabling it, also consider stale DNS caches in the system or apps.

DNS leakUnexpected query path: A DNS leak usually means queries did not take the intended network path—for example, a domain expected to be resolved through the proxy is sent to a local resolver instead. First clarify your split-routing policy to determine whether this is actually a problem; local DNS for domains routed direct may be expected. Check encrypted DNS in apps, system resolution settings, and core logs rather than relying only on the resolver location shown by a test page.

Proxy connection latencyProxy test: Proxy connection latency is usually measured by accessing a test destination through the selected proxy configuration and timing the request, so it covers more connection steps than a simple port probe. Results depend on the test address, DNS, timeout threshold, and current network conditions; values from different clients are not directly comparable. After a successful test, try the services you actually use and confirm the exit route is as expected. A speed test does not show the maximum available bandwidth.

V2Ray Glossary

Configuration layers at a glance

Protocols and transport

Cores and clients

Subscriptions and servers

Routing and split routing

Proxy modes and networking

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