1
vote
2answers
73 views

Wireshark TCP Window Size Value

I am debugging an application with Wireshark and watching the TCP Window Size value shrink on one side of the communication. If the packet's TCP section shows a "Window size value: 1", does that mean ...
1
vote
0answers
50 views

Simple tcp capture tool - output results like chat session? [closed]

I seek a tool which will capture TCP traffic with the resulting output looking almost like an iPhone SMS conversation. Something like: timestamps client stuff is left justified / green server stuff ...
-1
votes
2answers
112 views

block all packets in windows 7 (so nothing appears in wireshark)? Can anything locally installed do it?

is it possible to block all packets in windows 7, so that nothing appears in wireshark? I have tried choosing Block all for incoming. for outgoing, I see it has no block all option, just a block ...
0
votes
1answer
86 views

Linux unfriendly IIS/ASP.NET :-) : Quick download on windows but slow on linux [closed]

This particular web site (gops.tay.be) serves objects quick if I try to request the page using windows, but I get them very slow if trying using linux. There is no difference if I use browser or curl: ...
0
votes
0answers
80 views

How to get more NFS packet details from Wireshark?

How can I get Wireshark to give me details about NFS packets at this level of granularity? (as exemplified here here) Specifically, I am interesting in looking at the the "Stable" option toward ...
0
votes
0answers
279 views

Window Size goes to zero

We are seeing an issue with our web servers where a client is doing a HTTP POST and sending xml files. We are seeing weird behavior where we are sometimes only receiving part of the data. (Sometimes ...
2
votes
3answers
5k views

Excessive 'TCP Dup ACK' & 'TCP Fast Retransmission' causing issues on network. What's causing this?

I'm getting excessive TCP Dup ACK and TCP Fast Retransmission on our network when I transfer files over the MetroEthernet link. The two sites are connected by one sonicwall router, so the sites are ...
1
vote
1answer
257 views

trace ftp file data in wireshark

I am trying to analyze ftp traffic in Wireshark. I can see commands like Request: List, PORT. But after FTP Response 150: Opening data channel for directory list. what I see immediately is ...
2
votes
1answer
2k views

tcpdump capturing tcp resets by host

I am trying to figure out where my tcp resets on my webserver happen. I have the following capture: tcpdump -fnni bond0:-nnvvS -w dump.pcap 'tcp[tcpflags] & (tcp-rst) !=0' When I look at the ...
4
votes
1answer
5k views

Why does WireShark think this frame is a TCP segment of a reassembled PDU

Please find a small pcap file here illustrating my problem. I have a three-way TCP handshake, followed by two FIX logons. (FIX is a protocol used in trading.) The first FIX logon (frame 4) is ...
0
votes
0answers
279 views

How to interpret findings on TCP Send/Recv Buffers

I have an application running on a CentOS machine that connects to a remote DB server on another CentOS machine. Every once in a while, without any discernable warning signs, the application seems to ...
2
votes
2answers
132 views

Is TCP RWIN set by application or OS?

I have a situation where an application is listening on a TCP port and every once in a while, as seen in tcp dumps, gets its Receiving Window (RWIN) set to zero. When this happens, its Recv-Q stops ...
0
votes
3answers
76 views

Which bit represents which TCP flag?

For instance, a WireShark capture filter example I found - tcp[13] & 8 == 8 represents packets with PSH flags. How do I count the 8 ? Based on the wikipedia image, PSH is in the middle of ...
2
votes
2answers
806 views

Correct way to show only TCP packages in wireshark

I needed to write a filter that correctly outputs only TCP packets, the obvious way, and the way written in wireshark is just tcp but when I tried it, it showed me also http, tls (as far as I ...
1
vote
0answers
110 views

Website latency and bad tcp packets

I have multiple websites hosted on a Linode VPS and I'm having an issue with one of them: every page that I try to load has about 10 seconds latency. Apache logs are clean and the other websites on ...
7
votes
2answers
2k views

tcpdump: snaplen set to 0 but still get “Packet size limited during capture”?

Due to this problem, I'm going to sniff some packets on the MySQL server backend to see what happens: # tcpdump -vv -s0 -c 100 -i bond0 tcp port 3306 and host 192.168.3.87 -w ...
1
vote
0answers
72 views

Divert TCP connection

I am trying to divert a TCP connection. Given a client (C) which is connected to a router R and two servers (S1 and S2) are connected to the router, C initially connects to S1. I am trying to write an ...
0
votes
0answers
239 views

Packets dropped at endpoint NIC — Windows 2003

I have a virtualized Windows 2003 server that hosts one of my pieces of server software. The problem is that the port listener of this server doesn't get the client traffic sometimes. With Wireshark ...
4
votes
2answers
1k views

syn/ack sequence number confusion

I was looking at some random traffic in wireshark and came across this (using relative seq/ack numbers): 1. myIP -> 74.125.227.96 [SYN] seq=0 2. 74.125.227.96 -> myIP ...
0
votes
2answers
318 views

Needs help to understand the wireshark results of a data transferring

In my LAN, I have a router that runs a Samba server and my PC connects to the router. I wiresharked during uploading a file from my PC to the samba server. Below is a shortcut of the wireshark ...
1
vote
3answers
10k views

Troubleshoot large number of TCP retransmits / dup ack / segment lost

I have a problem with RDC slowing to a crawl or disconnecting entirely. Client is XP SP3 w/ RDC 6, server is Win 2k8 R2. Both have been scanned thoroughly and found to be virus free. I downloaded ...
0
votes
1answer
328 views

Tcp retransmission tcp session reconstruction

Im trying to write a program that reconstructs tcp sessions. I have a pcap file which have packets. The problem is i dont know which packets i should use to construct sessions when there is a ...
0
votes
2answers
641 views

How to use tshark to do this task

I don't have any base knowledge about tshark, and it is hard to find any tutorial to help me with this. So now I have a pcap file which consists a lot of network flows; a time range; an ip addr; a ...
0
votes
0answers
413 views

Why server is sending RST?

Scenario is : We have a server machine behind a DSL router to which multiple clients are connecting over internet. For few days it worked fine but from today we have observed frequent disconnection. ...
9
votes
4answers
48k views

What causes duplicate ACK records?

We're reviewing Wireshark captures from a few client machines that are showing multiple duplicate ACK records which then triggers retransmit and out-of-sequence packets. These are shown in the ...
0
votes
0answers
520 views

Socket Error 10054 & 10060

We are experiencing a problem after moving some software from one server to another. the client has remained on the same machine. Old Server: Windows 2003 server Physical machine New Server: Windows ...
5
votes
1answer
1k views

tcpdump filter for tcp zero window messages

Is there a pcap filter for TCPDump that will allow be to filter zero window messages? I know how to filter these in a wireshark display filter (tcp.analysis.zero_window) but the amount of data I ...
5
votes
2answers
8k views

How can I search the info column in WireShark?

WireShark | Windows I want to search a packet capture of SMTP traffic for specific addresses/messages. Normally, I just sort the info column and browse but it would be nice if I could just run a ...
1
vote
1answer
1k views

TCP RST Reset Every 5 Minutes on Windows 2003 sp2

Recently I had a web developer come to me and ask why he was receiving connection errors in his app that was accessing a sql database. So, I went through my normal trouble shooting steps to isolate ...
1
vote
0answers
843 views

TCP Zero Window with no corresponding Window Update

I am trying to debug a network issue and am using Wireshark and tcpdump to grab packets from my server. I have one client application that is grabbing all my available connections and then holding ...