Understand TCP 3 way handshake!

What is TCP 3 way handshake?

What is TCP. TCP means transmission control protocol, in short, this is a protocol to transmit data after a connection is made. You use TCP when you request a website for example. The handshake is what happens behind the scene. This is how you establish a connection before transmitting data.

Here it how it works!

When you request a website, your computer (client) will first send a packet with a SYN flag to the web server. SYN is short for SYNchronize. It's an attempt to open a connection. The server then respond with SYN flag and ACK flag to ACKnowledge the connection. Then your computer sends an ACK flag to confirm the handshake

http://3.bp.blogspot.com/_AamnZyf3C_A/TBvQXqrnqII/AAAAAAAAAY0/lf0Kndz8N8A/s1600/tcp+3+way+handshake.png

After the handshake is completed, the connection is open and the computer starts sending the data!

You can compare this to two persons starting a conversation.

first person: Hi, do you want to talk (SYN)
second person: Sure let's talk (SYN, ACK)
first person: Ok let's talk (ACK)

Then the conversation starts (data transfer)!

You will need this concept for the hacking series https://steemit.com/hack/@pierlave/learn-hacking-1-00-overview
This is a simplified explanation of how the handshake works, if you want more details or have any questions, feel free to ask!

@pierlave

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