UDP

UDP (User Datagram Protocol) exists at the transport layer but behaves nothing like TCP. There are no sessions, no acknowledgements, and no ordering guarantees — an application simply hands a datagram to the network and moves on, which is perfect when timeliness beats perfection.

Key Facts About UDP

• Stateless delivery: Datagrams leave immediately without any prior arrangement.
• Speed advantage: Skipping handshakes trims valuable milliseconds.
• Fire and forget: Nothing is guaranteed — not arrival, order, or integrity.
• Broadcast capable: A single send can address multiple recipients.
• Lightweight: 8-byte headers make room for more actual data.

UDP Forwarding with FlClash

FlClash supports UDP proxying, crucial for online gaming, video conferencing, and DNS queries. UDP support is toggled in the configuration:

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