Martin/Stephen
Thanks for the answers... I'm on travel at the moment and won't be back to 
look at this problem until Monday.  I did check for ACL's and Firewalls 
Blocks but I am not finding any... I'll keep looking.

Thanks,

Michael Ciccone
Network Engineer
eToys Direct, Inc.
Office:  303-226-8617
Cell:  720-299-1573
Fax:  303-226-8600
http://www.etoys.com



"Visser, Martin" <[EMAIL PROTECTED]> 
Sent by: [EMAIL PROTECTED]
05/21/2007 06:05 PM
Please respond to
Community support list for Wireshark <wireshark-users@wireshark.org>


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Subject
Re: [Wireshark-users] Help with Output "TCP Dup ACK3#2 1320 > 22 ACK






Duplicate ACKs are fairly common, so they don't always indicate a problem. 
During normal congestion you will receive duplicate ACKs if the far end 
has not received a TCP segment it believes it should have. It also can be 
used to keep alive a connection.
 
However if you get dup ACKs consistently at the start of a connection it 
might mean that there is some sort of firewall ACL blocking traffic. As 
Stephen said, it is important to know where this occurs during the 3 way 
handshake at the beginning of a connection or later on.
 
Martin Visser

Technology Consultant
Consulting & Integration
Technology Solutions Group - HP Services

410 Concord Road
Rhodes NSW  2138
Australia

Mobile: +61-411-254-513
Fax: +61-2-9022-1800 
E-mail: martin.visserAThp.com

This email (including any attachments) is intended only for the use of the 
individual or entity named above and may contain information that is 
confidential, proprietary or privileged. If you are not the intended 
recipient, please notify HP immediately by return email and then delete 
the email, destroy any printed copy and do not disclose or use the 
information in it.

  
 

From: [EMAIL PROTECTED] 
[mailto:[EMAIL PROTECTED] On Behalf Of Mike Ciccone
Sent: Saturday, 19 May 2007 7:57 AM
To: wireshark-users@wireshark.org
Subject: [Wireshark-users] Help with Output "TCP Dup ACK3#2 1320 > 22 ACK


Hello, 
I am having a problem with SSH.  I can ssh from some server but not 
others.  I verified that there are no access-lists blocking from doing 
this.  When I ran Wireshark on my pc and tried to ssh to the server I get 
the following line that could be telling me what the problem is. However, 
I don't understand it and was hoping some out there could explain it to 
me. 

Here is the line: 
[TCP Dup ACK 3#2] 1320 > 22 [ACK] Seq=1 Ack=1 win=65535 Len=0 

Does this mean anything to anyone?  I'm guessing my problem lies here.  If 
I ssh to a server that works... I don't see this line 

Thanks 

Mike C. _______________________________________________
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