commandline packet analyzer

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4
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3answers
4k views

How to capture last N seconds of packets using tcpdump

How can I capture the last N seconds of packets using tcpdump?
0
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1answer
5k views

How do I make tcpdump to write to file for each packet it captures?

I'm running the following version of tcpdump: tcpdump version 4.0.0 libpcap version 1.0.0 I want to make tcpdump write to a file for each packet it captures. Currently, I could only see the ...
2
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4answers
5k views

how to make tcpdump to display ip and port number but not hostname and protocol

I'm using tcpdump for some tests I want to see the IP and port number but the output of tcpdump is like IP pl1snu.koren.kr.http > kitch.pl.sophia.inria.fr.dnp: Flags [P.], seq 54:72, ack 1, win ...
0
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1answer
44 views

Why does tcpdump not come precompiled and how to compile it?

Hello I recently downloaded tcpdump from the www.tcpdump.org/ website, extracted the tar.gz file and found nothing but source and header files, I do not posses the necessary knowledge to get a working ...
0
votes
1answer
125 views

ipv6 ping host got destination host unreachable until run tcpdump

At first (all computer booted) when I ping the gateway (linux computer, two network cards(one is usb)) from a windows computer, I got: "Destination host unreachable", but when I run "tcpdump -i ...
1
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2answers
32 views

Can tcpdump be instructed not to report packets to a specific source?

I would like to monitor packets using TCPdump. Sadly, I must do this remotely - in this case, I'm using a remote desktop from VNC, but at best I can do it over SSH. What I mean by "at best" is: I am ...
12
votes
3answers
9k views

Can I monitor a local unix domain socket like tcpdump?

I'd like to monitor responses on a unix socket without disturbing the original connections and pipe them to a script for processing. I know how to do this with tcpdump for tcp connections but I ...
1
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0answers
43 views

What's wrong with this tcpdump syntax?

sudo tcpdump -i ath1 -s 0 -nne "(type mgt and subtype beacon)" Can anyone help me? I was following a tutorial at http://wiki.secarmour.com/2013/09/capture-wireless-traffic.html but seems I got ...
1
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3answers
316 views

Check if HTTP calls are gzipped

Assuming that I have an application server (Linux) running on port 80, how can I make sure (with tcpdump, I guess) that all incoming requests are gzipped and all responses are gzipped as well? Also, ...
0
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1answer
30 views

tcpdump prints nothing while trying to listen communication with sip server

The following command sudo tcpdump -nqt -s 0 -A -i eth0 port 5060 works and prints incoming SIP messages. Now I want to see entire communication and entering the IP address of the SIP server: ...
1
vote
2answers
108 views

tcpdump: how to get grepable output?

I am trying to troubleshoot an issue where I only have tcpdump available on an appliance. I want to use tcpdump to filter web traffic, and only display traffic containing certain strings. I do the ...
1
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0answers
210 views

how to sniff from a TP-Link ADSL modem?

I have a PC and a tablet that connected to a TP-Link ADSL modem. PROBLEM: I want to see the packets that send and receive from my modem not my PC( to see both wire and wireless packets) I search ...
0
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2answers
1k views

Why are some tcp packets with the RST flag classified as new incoming connection?

While looking through my iptables log, I keep observing periodically incoming connections with the RESET flag being set from a few ip addresses within my ISP's network. This is a sample tcpdump on one ...
0
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1answer
137 views

Captured packets with tcpdump vs. tcpdump > file

Why is there such difference in number of packets captured by tcpdump when the output is written to console and to file? $ tcpdump ... 1681 packets captured 1681 packets received by filter 0 packets ...
0
votes
1answer
465 views

Why does tcpdump take so long to read pcap files?

I am using a third-party tool that captures network traffic as a pcap file during a network test. When I attempt to play these files back, I use the tcpdump tool with the -Aq -r options, and pipe the ...
0
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2answers
979 views

Trouble with mergecap [ concatenation of pcap files ] - undesired info in output file

I hope somebody will be able to help me... The problem is with merging multiple .pcap files. Recently - like a week ago I've used a mergecap to merge mutiple pcap files into one. Everything worked ...
1
vote
2answers
397 views

How to quieten tcpdump output when reading a pcap file?

I notice that when using tcpdump to read a pcap file, the tcpdump command somehow manages to print information to my console even when I redirect both STDOUT and STDERR. How can I prevent tcpdump from ...
4
votes
3answers
43k views

What's all this deploy.akamaitechnologies.com traffic?

I happened to do a tcpdump while leaving my Mac idle, and when I came back after a mere half-hour there were something like 5000 packets involving deploy.akamaitechnologies.com, in which my computer ...
0
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1answer
44 views

Get external email from action “mailto”-form

Is it possible to pick out the email adress that a "mailto"-form will send an external email to? example from this (swedish "ebay" - ad) ...
0
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0answers
216 views

OpenVSwitch no traffic on bridge

I setup a bridge(br-int) with OpenVSwitch and plugged in eth3 which is connected to a hub. When other computers send traffic on this hub, I can get those traffic on eth3. However, if I try to do that ...
1
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0answers
111 views

No response received from github ssh randomly

My git pull started to stop working randomly with this error $ git pull ssh: connect to host github.com port 22: Connection timed out fatal: The remote end hung up unexpectedly I tried debugging ...
1
vote
2answers
140 views

Different packet sizes on Wi-Fi and 3G interfaces while tethering

I am using an application called android-wifi-tether on a mobile phone. My laptop is connected to the phone over Wi-Fi and the phone is connected to Internet over 3G. I am using tcpdump to sniff ...
0
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2answers
349 views

Packet filter logging [currently with tcpdump in background as root]

I am running OS X Mavericks and use the "packet filter" firewall. However, it seems that "pflogd" is not available. I found that you can create an interface named pflog0 and then use tcpdump to see ...
0
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2answers
643 views

how to use tcpdump to capture all packets on local network?

I have a home used wireless router, one linux laptop and android connected to it. Lets say the linux has ip 10.5.5.1, mac AA:AA:AA:AA:AA:AA and android has 10.5.5.2, mac AA:AA:AA:AA:AA:AB. The ...
0
votes
1answer
186 views

Detect HTTP sessions using tcpdump

I have a tracefile and I want to find all web servers that were successfully visited in the trace, contacted via HTTP. I'm using: tcpdump -r file.trace - tcp port 80 Maybe I have to search for a ...
0
votes
1answer
27 views

Is there a way to limit number of packet captures with tcpflow?

I want to limit the number of captured packets, such as: tcpdump -c 20 I want to use tcpflow instead. Is this possible? The console throws a syntax error using tcpflow with the -c parameter. edit - ...
0
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2answers
350 views

miss /dev/bpf in freebsd

I'm using tcpdump in freebsd, and I got the following error: $ /usr/sbin/tcpdump -i bge0 tcpdump: (cannot open device) /dev/bpf: No such file or directory a few google search indicate that the ...
3
votes
2answers
357 views

Filter packets sent via HTTP to a port other then 80?

I have a database communicating on port 7474 via HTTP (sigh), and I want to debug the queries sent to / from it. However, a filter such as http.request.method == "POST" Filters out every post ...
2
votes
1answer
447 views

Using tcpdump on displayed TCP data

If sudo tcpdump -i eth0 -X gives me tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes ...
3
votes
1answer
152 views

How to output a simple network activity plot in console in Linux?

There's tload that plots load average. There's iftop that network usage as bars. How to do something like this: # tcpdump -i eth0 --plot 'host 1.2.3.4' 13:45:03 | | 0 in 0 ...
1
vote
1answer
234 views

How to detect packets that are only from the local network and not from the ISP/internet?

I'm building a bandwidth monitor using JNetPcap(java version of libpcap/winpcap). I need to recognise packets within the home network so that I don' count them towards the total bandwidth used. I ...
0
votes
1answer
804 views

have tcpdump show the 'conversation' as i would get from wireshark?

Is it possible to get the same output i would get from: tcpdump port 80 -w log.pcap wireshark log.pcap in wireshark Analyze > Follow TCP Stream and then in the bottom drop down Entire ...
2
votes
1answer
109 views

LAN assembly 2 packets into 1 packets?

I have two computers A and B, there is a TCP connection between them. I use TCPdump to capture the packets. I notice that when A sends a lot of TCP packets to B, each IP packets are 1514 bytes. In ...
0
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0answers
19 views

Executing tcpdump remotely while storing packet capture locally [duplicate]

I have run into stumbling block while attempting to create a bash script that will write packet capture files from tcpdump onto a remote server, while displaying the output of the tcpdump command so ...
0
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0answers
589 views

Executing tcpdump remotely while storing packet capture locally

I have run into stumbling block while attempting to create a bash script that will write packet capture files from tcpdump onto a remote server, while displaying the output of the tcpdump command so ...
2
votes
2answers
3k views

tcpdump error: no suitable device found in Linux

Guys im trying to test a tcpdump to google.com (im new to Linux by the way). so here's what i typed in my shell: $tcpdump src 192.168.1.xxx and dst www.google.com and port ftp but i get this ...
0
votes
2answers
2k views

TCPDUMP: are these args consistent or meaningless together?

I'm using tcpdump on routing software, and trying to check whether the presence of ip/ip6 protocol with an ip6/ip host (i.e., the other IP family), or else specifying a mix of IPv4 and IPv6 IPs as ...
1
vote
1answer
1k views

How to set NIC in promiscuous mode on mac book air?

I am trying to run my nic on MacOSx at promiscuous mode and then use tshark / tcpdump Option1: ifconfig en0 promisc but I get this message: ifconfig: promisc: bad value Option 2: I tried sudo ...
0
votes
1answer
426 views

Detect HTTP sessions using tcpdump [closed]

I have a tracefile and I want to find all web servers that were successfully visited in the trace, contacted via HTTP. I'm using: tcpdump -r file.trace - tcp port 80 Maybe I have to search for a ...
1
vote
1answer
749 views

Record multicast stream on multi-homed Linux host

I have what sounds like the simplest possible use case, and yet nothing is satisfactory. I have a multi-homed host and I would like to listen to multicasts on eth1, and shove all the payload (NOT ...
1
vote
1answer
752 views

TCPDUMP -G option

Can anyone give me examples of the TCPDUMP -G use with 60 seconds as a example and incremental files? like : tcpdump -w %s -G 60 i try it but don't increment files only reset the file each ...
1
vote
1answer
403 views

What does this tcpdump printout mean?

I'm not very experience with networking, so on my free time, I usually try and learn some more things about the internet and how it works. While at school, I came across tcpdump and wanted to give it ...
4
votes
2answers
5k views

How to make tcpdump (or other tool) to actually dump TCP stream?

I expect something like this: $ nc example.com 80 GET / HTTP/1.0 HTTP/1.0 500 K.O. Content-Type: application/null Content-Length: -1 $ Meanwhile: # tcpdump -i eth0 --actually-dump-all-tcp ...
4
votes
2answers
7k views

tcpdump promiscuous mode on OSX 10.8

By examining my wireless router configuration I can see there's 2 IPs assigned: 192.168.1.100 -> laptop (Macbook Air OSX 10.8.2, where I runtcpdump) 192.168.1.101 -> ipad But then if I run: sudo ...
0
votes
1answer
543 views

How do I capture 802.11 headers on an AP while not in monitor mode?

I am wondering if it is possible to extract 802.11 frames on a router running OpenWrt operating as an access point. I tried using tcpdump and loading the dumped packets in Wireshark, but I could only ...
5
votes
1answer
2k views

Traffic between VirtualBox guests not showing up in tcpdump

I have a test environment setup with 4 VirtualBox guests running CentOS 6. Each has one network device attached to a bridged adapter, which is my primary network connection on my PC, with a static IP ...
4
votes
1answer
272 views

understanding the tcp header

The first 16 bits in a tcp header, (rfc793), are for the source port, right? The next 16 are for the destination port. When I run tcpdump -xx I can recognise MAC addresses of boxes on my system. Does ...
0
votes
1answer
486 views

Can't display RSSI values in Wireshark

I am trying to analyze the up-link Wireless traffic generated by my Sony Ericsson phone and captured by my D-Link router, on which I installed the DD-WRT firmware. To do this, first I log in the ...
2
votes
2answers
406 views

Is there a serious issue with setting the SUID bit on tcpdump?

I'm running tcpdump on a remote machine, and piping the output to Wireshark on my local machine over SSH. In order to do this, I had to set the SUID bit on tcpdump. For background, the remote machine ...
0
votes
2answers
542 views

TCP packets not captured by PHP listener

I have a device (GPS localizer) that is sending TCP (I think so) packets to my server on given IP address and through given port. Since I have only SSH access to that server, I opened up two sessions ...