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Questions tagged [packet-capture]

is for questions about capturing packets of various protocols that are transmitted over a network.

A lot of computer network protocols transmit their contents in packets. Packet capture is the interception of these packets as they are moved over a network of some type.

A packet sniffer captures raw data traveling over a network segment and saves it to a file for analysis.

Software

A software sniffer can generally only capture network data either originating from or going to the computer running it, plus any "broadcast" messages, if the computer is connected to the network via a switch. If the computer is connected to the network via a router, it may be able to capture network data for any device on connected to the same router.

Hardware

A hardware packet sniffer is physically connected to the network by connecting it to a router or switch. Sometimes the router or switch has to be configured to allow the sniffer to capture traffic being routed through it; this is called port mirroring.

Analysis

The captured data can be analyzed by the software that captured it, or by a program specifically designed to analyze the network data.

See Also

  • Wikipedia Article on Packet Analyzers
  • The term packet sniffer is also common and can be considered a synonym.
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Does capturing outgoing frames using linux raw socket require ETH_P_ALL

On Linux (2.6.39 kernel), using raw sockets, I'm trying to receive all the multicast frames that are sent out by the system itself. I created a raw socket socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));, and was reading the frames from the socket,…
Pawel Veselov
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writing a http sniffer

I would like to write a program to extract the URLs of websites visited by a system (an IP address) through packet capture.. I think this URL will come in the data section ( ie not in any of the headers - ethernet / ip / tcp-udp ).. ( Such programs…
trinity
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Using a linked list with counters for packet sniffing in C

I've been reading online and watching demo vids on how to use linked lists in C, and have a somewhat basic understanding of them now. Apologies in advance as my experience of C is both rusty and limited. I have an open source packet sniffer in C…
user3107379
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how to solve errors like ‘struct iphdr’ has no member named ‘daddr’

I ran a program ( the link is - http://www.security-freak.net/raw-sockets/sniffer_eth_ip_tcp.c ) in my fedora core 5. On compilation , i get the following errors : [root@localhost ~]# gcc sniffer_eth_ip_tcp.c In file included from…
trinity
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How to filter wireshark to display only packets between a server and a client?

I am new to wireshark and trying to write simple filters. What i am trying to do is the following: I want to write a filter so that only the packets between my computer and a specified server appear in the packets pane. Here is what i…
yrazlik
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intercepting network data from a particular program

im looking for a way to detect, and capture data being sent TO and FROM a specific program, ive attempted to use something like wireshark but it all seems to be a bunch of nonsense to me, so i was wondering if anybody could help me get the data,…
Nick
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Listening on Virtual Interface

My objective is to create a to create a virtual wireless interface and to attach a listener on that interface. I am trying to do this using a C program. So far I have been able to create the virtual interface by the following methods : Using the…
Aditya Pawade
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add builder.addRoute("0.0.0.0",0) causing the packets not to be routed to destination

I'm new to android development and I'm trying to capture packets in android. When I add builder.addRoute("0.0.0.0",0) to my code , it's helping me capture packets, but those packets are not being routed to there destination. Did anyone come across…
Yogi
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How to capture packets off other machine?

I want to capture packets from other computers on my network. I have 3 computers in total on same SSID and I want to capture packets off these 2 other computer. How to? I have tried using wireshark but it only shows packets that being sent to/from…
user2632160
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Packet sniffer only detects sent packets

I have been working on a packet sniffer just for fun/education and it's been going quite well. The problem that I'm having is that the only packets appearing in recvfrom() are SENT packets i.e. packets with my IP as their source IP and not my WAN IP…
Robert
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How to decode and play back rtp captured packets using Wireshark?

I have captured packets of RTP in Wireshark The captured packets are of .mp3, and now how should I decode these packets, so that I can play them back again in any player? Is there a way to decode these captured packets, either it be audio or video…
c-vang
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how to display flowid alongwith frame number for each packet of a pcap using tshark/wireshark

Is there any concept of flow id in tshark ? When i searched for filters, i found out that tcp.stream exists but its equivalent for udp i.e udp.stream doesn't exist. When i open a pcap, by default it shows the frame number, ip addresses, info etc. In…
mezda
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Any good .net packet sniffers around?

I am looking for one to use from my c# application. Anyone knows a free one?
devoured elysium
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Remove duplicated packets using jnetpcap

I have an application in Java that analyses .pcap files using jnetpcap library. I need to remove all the duplicated, retransmitted and out-of-order packets. Is there any way I can use the jnetpcap library to do that? At least to remove the…
user1454263
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Efficient Searching Algorithm for Capture File

I am currently developing a tool in java that will help track and interpret data being sent across an ethernet connection. I have already successfully developed both the packet sniffer and the packet data interpreter. I run into a problem when…
Rob Wagner
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