Solved

WireShark - Capture Filter - FIN packets only

Posted on 2010-11-10
2
1,892 Views
Last Modified: 2012-05-10
Hi All,

I'm troubleshooting a WAN Telnet disconnect problem that only occurs after 1-2 hours of inactivity.  The terminal emulation software vendor tells me I need to look for "FIN" packets for finding what device is terminating the connection.  Since there will be so much traffic in 1-2 hours, I'd like to just capture any packets that contain "FIN".

Can you help me with building the Capture Filter to accomplish this?

Thanks,
Dave
0
Comment
Question by:dsstao
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 14

Accepted Solution

by:
Otto_N earned 500 total points
ID: 34102485
'tcp[tcpflags] & tcp-fin != 0'  should do the trick (without the quotes, of course).

However, there can be quite a lot of TCP connections closing.  If you want to capture only packets to and from a particular host, add 'and host 10.10.10.1' to the capture filter.
0
 
LVL 1

Author Closing Comment

by:dsstao
ID: 34103671
Thank you, YDM
0

Featured Post

Webinar: Aligning, Automating, Winning

Join Dan Russo, Senior Manager of Operations Intelligence, for an in-depth discussion on how Dealertrack, leading provider of integrated digital solutions for the automotive industry, transformed their DevOps processes to increase collaboration and move with greater velocity.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
new to networking configuration 6 77
network + 7 89
Is WiFi half-duplex or Full -duplex 4 74
Security considerations & assessment when enabling Cisco Wake-On-Lan 5 54
How to set-up an On Demand, IPSec, Site to SIte, VPN from a Draytek Vigor Router to a Cyberoam UTM Appliance. A concise guide to the settings required on both devices
David Varnum recently wrote up his impressions of PRTG, based on a presentation by my colleague Christian at Tech Field Day at VMworld in Barcelona. Thanks David, for your detailed and honest evaluation!
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question