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tcp syn

Hi all, when I make a connection to a server etc, is the first message a tcp syn, is this the handshake?

2 REPLIES
Cisco Employee

Re: tcp syn

yes

Re: tcp syn

It's the "first" packet of a "three-way" handshake.

1. Client sends SYN

2. Server sends SYN/ACK

3. Client sends ACK

It's used to synchronize sequence numbers, and to verify that each side received the other's message.

Tearing down a TCP connection is a four-way handshake.

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