Networking

DTLS (Datagram Transport Layer Security)

A variant of TLS designed to run over UDP instead of TCP, adding explicit sequence numbers, handshake retransmission, replay windows, and a stateless cookie exchange so encryption survives packet loss and reordering. VPN gateways use it for low-latency tunnels, and its extra parsing code runs before authentication.

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How DTLS Works and Why It Widens a VPN Gateway's Attack Surface

DTLS carries TLS over UDP for faster VPN tunnels, and it is usually on by default. What the protocol adds, why that code is pre-authentication attack surface, and how to decide whether to disable it.

intermediate 6 min read

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