Wireshark-users: [Wireshark-users] TCP Previous segment lost, TCP dup ACK
From: Thomas Ellingsén <Thomas.Ellingsen@xxxxxxxxxxx>
Date: Mon, 19 Apr 2010 15:10:29 +0200
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 in what 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