Wireshark mailing list archives
Re: TCP Previous segment lost, TCP dup ACK
From: Martin Visser <martinvisser99 () gmail com>
Date: Wed, 21 Apr 2010 15:01:50 +1000
Thomas, The message "TCP Previous segment lost” refers to the fact that the SEQ in packet 3381 has jumped ahead from the next SEQ expected from 192.176.3.132. Wireshark is showing can't show the missing packet, so shows it in the next segment from that source. The receiver also has detected a segment went missing, and wants it quickly and hence the triple-ACK Regards, Martin MartinVisser99 () gmail com On Wed, Apr 21, 2010 at 12:47 AM, Thomas Ellingsén < Thomas.Ellingsen () crosskey se> wrote:
Hi Martin, Ok, I agree. But the thing that confuses me is the dup ACK that is ”requesting” the fast retransmission is comming from 10.32.22.90 and the dup acks are always post a ” TCP Previous segment lost” originated from 192.176.3.132 witch in my mind indicates that 192.176.3.132 is missing a packet sent from 10.32.22.90. Someone please enlighten a lost ”networker”! Regards, Thomas *From:* Martin Visser [mailto:martinvisser99 () gmail com] *Sent:* den 19 april 2010 15:27 *To:* Community support list for Wireshark *Subject:* Re: [Wireshark-users] TCP Previous segment lost, TCP dup ACK I'd pretty certain that this 10.33.22.90 hoping to invoke Fast Retransmit - http://en.wikipedia.org/wiki/Fast_retransmit Regards, Martin MartinVisser99 () gmail com On Mon, Apr 19, 2010 at 11:10 PM, Thomas Ellingsén < Thomas.Ellingsen () crosskey se> wrote: Hi, I get TCP Previous segment lost folowed by 2-10 TCP Dup ACK 3381 2010-04-19 12:33:55.284770 192.176.3.132 10.32.22.90 TCP [TCP Previous segment lost] [TCP segment of a reassembled PDU] 3382 2010-04-19 12:33:55.286392 10.32.22.90 192.176.3.132 TCP [TCP Dup ACK 3379#1] 56791 > 29900 [ACK] Seq=1 Ack=269280 Win=254 Len=0 SLE=270296 SRE=270660 3384 2010-04-19 12:33:55.333856 10.32.22.90 192.176.3.132 TCP [TCP Dup ACK 3379#2] 56791 > 29900 [ACK] Seq=1 Ack=269280 Win=254 Len=0 SLE=270296 SRE=270723 3387 2010-04-19 12:33:55.478371 10.32.22.90 192.176.3.132 TCP [TCP Dup ACK 3379#3] 56791 > 29900 [ACK] Seq=1 Ack=269280 Win=254 Len=0 SLE=270296 SRE=270791 ...From what I understand there is lost packets. Is there any way to see inwhat direction the packets are getting dropped/lost? Why is 10.32.22.90 sending the same ACK multiple times? Is "he" waiting for a response on the ACK?? It does not make sence to me. Regrads, Thomas ___________________________________________________________________________ Sent via: Wireshark-users mailing list <wireshark-users () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-users Unsubscribe: https://wireshark.org/mailman/options/wireshark-users mailto:wireshark-users-request () wireshark org ?subject=unsubscribe
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Current thread:
- TCP Previous segment lost, TCP dup ACK Thomas Ellingsén (Apr 19)
- Re: TCP Previous segment lost, TCP dup ACK Martin Visser (Apr 19)
- Re: TCP Previous segment lost, TCP dup ACK Thomas Ellingsén (Apr 20)
- Re: TCP Previous segment lost, TCP dup ACK Martin Visser (Apr 20)
- Re: TCP Previous segment lost, TCP dup ACK Thomas Ellingsén (Apr 20)
- Re: TCP Previous segment lost, TCP dup ACK Martin Visser (Apr 19)