Differences between version 3 and predecessor to the previous major change of TcpStates.
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| Newer page: | version 3 | Last edited on Thursday, October 9, 2003 1:17:24 pm | by DiegoBohman | Revert |
| Older page: | version 1 | Last edited on Saturday, November 23, 2002 3:07:16 pm | by PerryLorier | Revert |
@@ -1,4 +1,13 @@
States of a [TCP] connection. These can be seen with
netstat -at
-;CLOSE_WAIT:After a TCP connection has been closed, the spec says you should make sure that the connection is not reopened for a few minutes to prevent packets that were delayed in the Internet causing the connection to be reopened. These will disappear by themselves after a while. This can cause problems on servers that have lots of very short connections (such as a web server) by filling up the OS's connection table.
+;CLOSED:A theoretical state where a [TCP] connection doesn't exist yet.
+;LISTEN:A state where [TCP] connection is waiting for a connection to be made to it.
+;SYN_RCVD: A [SYN] has been received, a SYN ACK has been sent, and we are waiting for an [ACK]
+;SYN_SENT: A [SYN] has been sent to start a connection, the SYN ACK hasn't yet been received.
+;ESTABLISHED: A connection has been established
+
;CLOSE_WAIT:After a [
TCP]
connection has been closed, the spec says you should make sure that the connection is not reopened for a few minutes to prevent packets that were delayed in the Internet causing the connection to be reopened. These will disappear by themselves after a while. This can cause problems on servers that have lots of very short connections (such as a web server) by filling up the OS's connection table. See also [EADDRINUSE]
+;LAST_ACK:A FIN has been received, we've sent our own FIN, but we are waiting on the ACK before we can move to the closed state.
+;FIN_WAIT_1:A FIN has been sent, waiting for a ACK or FIN
+;FIN_WAIT_2:A FIN has been sent, and an ACK has been received. More data can be received. This connection is half open.
+;CLOSING:A FIN has been sent, and one received, the FIN hasn't been ACK'd yet
.
