Building a webserver, client doesn't acknowledge HTTP 200 OK frame.

Posted by Evert on Stack Overflow See other posts from Stack Overflow or by Evert
Published on 2010-04-07T11:43:42Z Indexed on 2010/05/11 10:04 UTC
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tcp

|

http

|

wireshark

Hi there, I'm building my own webserver based on a tutorial. I have found a simple way to initiate a TCP connection and send one segment of http data (the webserver will run on a microcontroller, so it will be very small)

Anyway, the following is the sequence I need to go through:

receive SYN
send SYN,ACK
receive ACK (the connection is now established)
receive ACK with HTTP GET command
send ACK
send FIN,ACK with HTTP data (e.g 200 OK)
receive FIN,ACK <- I don't recieve this packet!
send ACK

Everything works fine until I send my acknowledgement and HTTP 200 OK message. The client won't send an acknowledgement to those two packages and thus no webpage is being displayed. I've added a pcap file of the sequence how I recorded it with wireshark.

Pcap file: http://cl.ly/5f5 (now it's the right data)

All sequence and acknowledgement numbers are correct, checksum are ok. Flags are also right. I have no idea what is going wrong.

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