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Okay, the user sent "SYN". Let me think about what that means. SYN is a common term in networking, right? It stands for Synchronous Transmission. But wait, maybe they're referring to the TCP handshake, which uses a SYN packet. I should cover both possibilities.
First, I'll explain Synchronous Transmission. It's a method where data is sent in a sequence of bytes with a start and stop bit, used for error detection. Then, the TCP SYN packet is part of the three-way handshake. I should mention how it works in establishing a connection. Also, maybe touch on SYN flooding attacks as a security concern. Let me make sure to keep it clear and not too technical. Let me structure it step by step.
The term "SYN" can refer to two distinct concepts in networking:
1. Synchronous Transmission (SYN in Data Communication)
Definition: A method of data transmission where characters (or bytes) are sent in a fixed sequence, with a start bit and stop bit to mark the beginning and end of each character.
Key Features:
Uses a clock signal to synchronize sender and receiver.
Common in older serial communication (e.g., RS-232).
Ensures error detection via parity bits (optional).
Example: A start bit is sent first, followed by data bits, a parity bit (if used), and a stop bit.
2. SYN in TCP Handshake (Network Layer)
Definition: A control packet used in the three-way TCP handshake to establish a connection between a client and server.
How It Works:
Client sends a SYN packet (with a random Sequence Number SYN=1).
Server responds with a SYN-ACK packet (acknowledges the client's SYN and sends its own SYN=1).
Client sends an ACK to confirm the server's SYN.
Purpose: Ensures both devices agree on the initial sequence number for data transmission.
Security concern: SYN Flood attacks exploit this process to overwhelm servers with fake handshake requests.
3. SYN Flood Attack
What it is: An exploit where attackers send a high volume of spoofed SYN packets to consume server resources.
Impact: Disables legitimate services by exhausting bandwidth and connection tables.
Mitigation: Firewalls, rate-limiting, and SYN Cookies ( delay acknowledging SYN packets until resources are available).
Let me know if you'd like further details! 馃槉
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发表于 2025-11-7 02:50:41