Solved

FTP data is identified as window update in Wireshark

Posted on 2011-09-14
4
706 Views
Last Modified: 2012-06-21
In the expert info composite screen the ftp data packets show up as windows update?

Group        Protocol     Summary                Count
Sequence  TCP            Window Update     37856

Is this normal? Does the wireshark dissector not identify FTP data correctly?

Or do I have a lot of windows update traffic on the network?
0
Comment
Question by:Dragon0x40
  • 2
  • 2
4 Comments
 
LVL 6

Accepted Solution

by:
netjgrnaut earned 500 total points
ID: 36539309
A TCP Window Update packet should not be confused with a "Microsoft Windows Update" packet (which Wireshark wouldn't identify as such, anyway).

Explanation from http://ask.wireshark.org/questions/901/expertmessage-window-update...

A packet marked "TCP Window Update" simply indicates that the sender's TCP receive buffer space has increased. Look at the previous packet from the sender - note the Window Size value in the TCP header. Then look at the "TCP Window Update" packet's Window Size setting.

What triggers these "TCP Window Update" packets? When an application picks up data from the receive buffer there is now more receive buffer space available. Wireshark sees the Window Size field value has increased and marks it to let you know the Window Size field has increased.

This is normal network behavior. Problem behaviors would be Zero Window conditions.

Hope that helps!
0
 

Author Comment

by:Dragon0x40
ID: 36539392
In the experts infos:

I have no errors

I have these warnings:

Window is full   20

Zero Window   17

ACKed lost segment (common at capture start)  63

Previous segment los (common st caputre start)  78

Out-Of-Order segment   187

Fast retransmission (suspected)  14

This was on a 1gb ftp file transfer
0
 
LVL 6

Expert Comment

by:netjgrnaut
ID: 36539494
Is this a new question?

Wireshark is not mis-identifying your FTP traffic.
The Window Update packet has nothing to do with MS Windows Update.

So... what's the question?
0
 

Author Comment

by:Dragon0x40
ID: 36539527
I will open a new question.
0

Featured Post

IT, Stop Being Called Into Every Meeting

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

Join & Write a Comment

Large and small networks have one same need, Service monitoring. Service monitoring consists of watch services of the several servers in the network. To monitor means that the administrator will receive an alert when a service is down or it's state …
Problem Description:   Couple of months ago we upgraded the ADSL line at our branch office from Home to Business line. The purpose of transforming the service to have static public IP’s. We were in need for public IP’s to publish our web resour…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

708 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

Need Help in Real-Time?

Connect with top rated Experts

16 Experts available now in Live!

Get 1:1 Help Now