Wireshark-users: Re: [Wireshark-users] Help with Output "TCP Dup ACK3#2 1320 > 22 ACK
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"
<martin.visser@xxxxxx>
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05/21/2007 06:05 PM
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Subject
| Re: [Wireshark-users] Help with Output
"TCP Dup ACK3#2 1320 > 22 ACK |
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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: wireshark-users-bounces@xxxxxxxxxxxxx
[mailto:wireshark-users-bounces@xxxxxxxxxxxxx] On Behalf Of Mike
Ciccone
Sent: Saturday, 19 May 2007 7:57 AM
To: wireshark-users@xxxxxxxxxxxxx
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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