UDP

UDP (User Datagram Protocol) is a transport-layer protocol built for speed over ceremony. It skips connection setup entirely and fires datagrams at their destination without promises — no delivery guarantee, no ordering, no deduplication.

Characteristics of UDP

• Connectionless: Data goes out immediately, no handshake involved.
• Low latency: No setup overhead makes it faster than TCP for short exchanges.
• Best effort: Delivery, order, and error recovery are left to the application.
• Multicast/broadcast: One packet can reach many receivers at once.
• Small footprint: An 8-byte header keeps overhead minimal.

UDP Through FlClash

FlClash supports UDP proxying, which matters for online gaming, voice/video calls, and DNS resolution. When a node has UDP enabled, datagram traffic is forwarded through the tunnel:

• udp: true: Enable UDP support in the configuration
• mode: udp: Set proxy mode to handle UDP traffic