FIN_WAIT_2 Timer, ~ and other assorted timers

Just viewing Proving It’s Not the Network with Path Analysis and thought, BEFORE watching this video, Ill check extactly what is currently connected to this laptop using netstat -a, which provided some info.

Often have 30 to 50 tabbed pages open in a browser, and three (3) largish bittorrent videos, and email, all needing to ‘connect-to-internet’, so the list from a netstat equiry is very long. Use: ‘netstat -a > netstat.txt‘ to capture the query-content into a plain text file.

VIDEO LINK-ABOVE ~ [quote] we explore how to quickly determine if the network is involved in the performance problem, or if it is free from blame. [end quote]

The netstat -a lists a number of connections with “FIN_WAIT_2 Timer” –

FIN_WAIT_2 Timer – (What exactly is this -?-)
The simplest definition that I see, (without getting all technical) is pasted below.

TCP/IP Security
www.linuxsecurity.com/resource_files/.../tcpip-security.html
A FIN_WAIT_2 timer is started when there is a transition 
from the FIN_WAIT_1 state to the FIN_WAIT_2 state. 
The value of this timer is 10 minutes.

For the other assorted timers? (title reference) – visit
#1: – http://netlab18.cis.nctu.edu.tw/TAi/Research/TCPIP/TCP Timers.ppt
I have no intention to explain in detail, … (just a quick overview / definition)

[SLIDE-2 of 24] ~ The 7 Timers for each Connection

Connection-Establishment Timer
* Establish a new connection.
* If a response isn’t received within 75 seconds, the connection establishment is aborted.

Retransmission Timer
* Based on Round-Trip Time (RTT).
* TCP sends data.
* When this timer expires, TCP retransmit the data.

GOOGLE-SEARCH – identify active connections using netstat -a

About grdanson

Maintainer and Administrator
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