Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations SkipVought on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

TIME_wait or syn_wait_1 1

Status
Not open for further replies.

78mike78

MIS
Feb 14, 2008
70
0
0
US
Can someone tell me what this means when i do a netstat TIME_wait or syn_wait_1.
Thanks.
 
Read RFC 793 as background - excerpt below.
The time-wait is when a tcp connection is already closed but the server will make sure that all data is recieved. This can be a problem on typically a web server where 1000's connectiosn are established and closed.
You can force the server to release these resources by sending a RST, instead of a normal session tear-down, e.g Fin - Fin/Ack etc.
You can also change the time-wait-delay in the registry / kernel to release the socket resources quicker than 2-minutes.
Hope this helps
Reon
From RFC 793 ...
Current Segment Variables
SEG.SEQ - segment sequence number
SEG.ACK - segment acknowledgment number
SEG.LEN - segment length
SEG.WND - segment window
SEG.UP - segment urgent pointer
SEG.PRC - segment precedence value

A connection progresses through a series of states during its lifetime. The states are: LISTEN, SYN-SENT, SYN-RECEIVED,ESTABLISHED, FIN-WAIT-1, FIN-WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK,TIME-WAIT, and the fictional state CLOSED. CLOSED is fictional because it represents the state when there is no TCB, and therefore, no connection. Briefly the meanings of the states are:

LISTEN - represents waiting for a connection request from any remote TCP and port.

SYN-SENT - represents waiting for a matching connection request after having sent a connection request.

SYN-RECEIVED - represents waiting for a confirming connection request acknowledgment after having both received and sent aconnection request.

ESTABLISHED - represents an open connection, data received can be delivered to the user. The normal state for the data transfer phase of the connection.

FIN-WAIT-1 - represents waiting for a connection termination request from the remote TCP, or an acknowledgment of the connection termination request previously sent.

FIN-WAIT-2 - represents waiting for a connection termination request from the remote TCP.

CLOSE-WAIT - represents waiting for a connection termination request from the local user.

CLOSING - represents waiting for a connection termination request acknowledgment from the remote TCP.

LAST-ACK - represents waiting for an acknowledgment of the connection termination request previously sent to the remote TCP(which includes an acknowledgment of its connection termination request).

TIME-WAIT - represents waiting for enough time to pass to be sure the remote TCP received the acknowledgment of its connection termination request.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top