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21
votes
3answers
9k views

How does Router know where to forward packet

If several computers with local addresses (192.168.0.#) are connected to a router and each computer opens a web browser and requests a page over HTTP, when these TCP:80 packets are sent out, the ...
8
votes
4answers
12k views

What's the minimum size of a TCP packet

A post here: http://blogs.adobe.com/dreamweaver/2011/02/optimal-css-tiled-background-image-size.html staes that "The smallest download that browsers can do is 1K bytes." Is this due to minimum size ...
8
votes
5answers
6k views

Capture live streaming

I want to capture a rtmp stream. The videos are live, different every day and usually i cant tune in because i am busy at work doing something :(. I would like to capture the stream however they use ...
7
votes
2answers
896 views

On an unencrypted public wi-fi hotspot, what exactly is a packet sniffer doing to get another computer's packet?

I get mixed results when reading information security articles, some of them stating that in order to do something similar you need to also setup some sort of honeypot with a running access point and ...
6
votes
5answers
9k views

How do IP answer packets reach their destination inside of a private LAN?

This is a little theory question that has been confusing me for a pretty long time. Basically, if we are inside of a private LAN, and we want incoming packets to reach, for example, an HTTP server ...
6
votes
2answers
576 views

Packet sniffing tools

OS: Windows XP Is there any tool that can do packet sniffing by processes? I use Wireshark before, but that's too wide. I need just to look into a certain process.
5
votes
2answers
5k views

What does the MySQL “max_allowed_packet” setting actually control?

We've been cleaning up database problems for the last four hours, thanks to a broken mysqldump that wasn't sufficiently erroring out. We were getting these errors: mysqldump: Error 2020: Got packet ...
5
votes
1answer
21k views

Capturing wireless traffic (using Wireshark)

When I run wireshark on a wired network it works fine and reports all of the packets. When I run it on a wireless network though I only see my own traffic. The wireless card I have is supposed to ...
4
votes
1answer
4k views

How to enable “packet forwarding” in OS X

How is it possible to enable packet forwarding in Mac OS X? Google gives me tons of hints for Windows and Linux but not for OS X.
4
votes
3answers
7k views

Packet Sniff over Wi-Fi

I've got a non-PC wireless client, and I'm wondering about some of its connections. I want to see the actual packets being exchanged from the net to my device over a Wi-Fi connection. I have ...
3
votes
11answers
10k views

What's the difference between a TCP segment and a TCP packet?

Is a TCP segment not part of a TCP packet? Here's what I've read: A segment is a piece of application data chopped into a transportable size by TCP and wrapped with a TCP header Isn't the TCP ...
3
votes
2answers
1k views

What are ping packets made of?

What exactly are in the packets that are sent via the ping command? I was reading a Wikipedia article about magic numbers and saw this: DHCP packets use a "magic cookie" value of '63 82 53 63' ...
3
votes
1answer
362 views

Relation between a packet and a frame over the network

I am learning how networks work and I have a question. What is actually sent over the network? A packet/datagram or a frame? I believe it is a packet. If so, let's say Computer A wants to communicate ...
3
votes
2answers
2k views

How do I trace HTTP packets with Wireshark?

What can I do in order to see packets that come from different sessions in a web page? For example when I open yahoo.com there are different sessions in yahoo; I dont know how to see which packet is ...
3
votes
3answers
166 views

Packet travelling in layers

I want to know how a network packet travels through different layers, i.e. from the physical layer to the presentation layer in Linux systems. Are there any detailed articles or books on this topic ...
2
votes
3answers
754 views

Will VPN will slow down VOIP traffic?

If I have a Linux setup with VPN in Paris and a Linux setup with VPN in London, both with high-speed internet, will packet-switching be slower for VOIP than if I didn't use VPN? A few people have ...
2
votes
4answers
85 views

How does badBIOS jumps airgaps? [closed]

I was reading this article from Ars on badBIOS and came across this line which states the malware, has the ability to use high-frequency transmissions passed between computer speakers and ...
2
votes
2answers
159 views

Continuous packets receive from Internet even when closing browsers,why is that?

I use windows XP sp3 on an HP laptop compaq nc6400 connecting to the net through adsl connection in a local network, as soon as I connect to the internet it starts to receive packets, is a virus doing ...
2
votes
5answers
161 views

Trying to understand IP packet flow

So I'm having trouble understanding how packets travel from one machine to another. Below I've put in an example of Computer 1 trying to connect to Computer 2. Computer 1 IP: 192.168.1.11 Subnet: ...
2
votes
2answers
4k views

Are Segments, Packets and Frames the same size if we ignore headers?

I've looked for some explanation about the differences between Segments, Packets and Frames, and from what I read: Segment is the original data + Transport Layer header. Packet is a Segment + ...
2
votes
3answers
184 views

Send cookies/site login information over my internal network?

Is there a way I can send cookies/site login information to computers within my internal network? i.e push them through in packet headers? Not FTP. For example if I want to send cookies with my ...
2
votes
1answer
647 views

Change TCP sequence numbers for packet replay?

First off, I'm using wireshark for capture and colasoft for replay. I'm attempting to replay a group of captured packets back, looped to be done several times over (the purpose of this is just to send ...
2
votes
2answers
2k views

FFMPEG Errors: “max_analyze_duration” “buffer underflow” “packet too large” What to do?

I have an error while just copying a video with ffmpeg. I use the command: ffmpeg -i leon.mpg -vcodec copy -acodec copy leon2.mpg The errors: [mpeg @ 00000000020ebd20] max_analyze_duration 5000000 ...
2
votes
1answer
428 views

How do I know if my packet requests are being redirected from localhost?

So I just had a fun and exciting time trying to figure why on earth a particular computer was able to ping different places on the interweb but not browse any webpages of the same places I was able to ...
2
votes
2answers
1k views

Linux Kernel Packet Forwarding Performance

I've been using a Linux box as a router for some time now. Nothing too fancy, just enabling forwarding in the kernel, turning on masquerading, and setting up iptables to poke a few holes in the ...
2
votes
0answers
38 views

Modify incoming packets before forwarding in Linux

I’m using a Linux (Debian based) system on which IP forwarding is enabled (/proc/sys/net/ipv4/ip_forward is set to 1). I can read the incoming packets using a raw sockets program, but I want to modify ...
2
votes
0answers
1k views

Drivers for packet injection on the Intel Centrino(R) Advanced N 6205

I have an Intel Centrino(R) Advanced N 6205, running BackTrack 5 in VMWare. I'm having trouble following the tutorial on aircrack-ng website, and I need to know what drivers to download to support ...
1
vote
2answers
138 views

What programs can I use to see what traffic of mine a network admin can see?

What programs can I use to see what traffic of mine a network admin can see? Monitor incoming and outgoing network traffic at a the packet level, I want to make sure my VPN is working properly.
1
vote
1answer
667 views

Capture network traffic from Playstation

I want to capture network traffic from my playstation. It is connected to my wireless network. For some reason Ethereal (now WireShark) isn't letting my use my wireless card to see traffic. Is it a ...
1
vote
1answer
166 views

TCP vs UDP. Sending data on a closed port

I try to understand differences between TCP and UDP packet on the error-checking. I know that UDP packets are connectionless and doesn't care that the packet will arrive the destination safely. And ...
1
vote
2answers
128 views

Layer 2 switching or Layer 3 forwarding?

I have a wireless router installed at my home (provided by ISP). Scenario: Router IP: 192.168.1.1 My Machine IP (X): 192.168.1.2 IP of machine Y: 192.168.1.3 Now when I ping Y from my ...
1
vote
1answer
2k views

Jumbo Packet vs Transmit Buffers

I want to increase the transfer speed between two network adapters: 1) Atheros AR8152 PCI-E Fast Network Adapter. 2) Marvell Yukon 88E8053 PCI-E Gigabit Ethernet Controller. Marvell has a "Jumbo ...
1
vote
1answer
189 views

Odd internet packet routing

I want to know is there anyway to explicitly control the packet routing. I try to connect my computer in HK from San Francisco. It is extremely slow and I use tracert to see what is going on. It seems ...
1
vote
1answer
125 views

Why HTTP response is split in 2 parts: header and body?

I'm trying to understand why a single HTTP response is split in 2 parts in the following setup: Requested resource is protected by HTTP Digest Authentication on server side. Communication is ...
1
vote
1answer
2k views

What is most likely to cause this packet loss?

This question: Can a software cause a huge ping response is what made me realize that I have a network problem. As you can see here: C:\Users\*****>pathping google.com Tracing route to ...
1
vote
1answer
149 views

How can I filter incoming packets to my application?

I have only little experience with Wireshark. The problem is that when my server (3rd party app) receives a faulty packets, it crashes. I would need to filter the incoming packets and filter out such ...
1
vote
2answers
839 views

TCP\IP Packet Signature - how to identify such data packets?

I know of a program that can "carve" (look for) TCP IP Packets from raw binary data. The results it presents are the source and destination MAC addresses, the source and destination IP addresses and a ...
1
vote
1answer
2k views

Can I have Tshark not truncate my urls

I've been using tshark recently and I've noticed that on certain urls it truncates the URL: Request URI [truncated]: ...
1
vote
1answer
213 views

Win7 Modifying incoming HTTP packet from specific url automatically

Is there an application that can listen in on my PCs http traffic (Preferably process specific), and modify packets that were requested from a certain url ? So let's say everytime I request ...
1
vote
2answers
546 views

Why cocoa packet analyzer shows “capture packets to a trace file” menu?

I am trying to use 'cocoa packet analyzer'('C.P.A'). I uses mac OSX and I installed this from appstore. After installed this, when I launch this program a popup comes out. Others say that to get ...
1
vote
1answer
112 views

Unexplained Log Cruft and Possible Dropped Packets on WPA2-Personal LAN

I've been receiving a LOT of log cruft ever since I installed my WUSB100V2 (using the rt2870sta community driver from the Linux kernel) and was wondering what it all meant. Many times when these ...
0
votes
5answers
2k views

Intercept email and see its content

My new company has a monitor position. What a monitor does, is to monitor what anyone is doing. No IM, USB, phone with camera are allowed. I wonder within a WLAN, if a monitor can intercept my email, ...
0
votes
2answers
2k views

Size of an IP Packet

What is the complete size of an IP Packet?
0
votes
3answers
1k views

Network Sniffer identifying strange requests to *.crdui.com

So I just downloaded a Network Sniffer on my local machine, as I think something is going on. As soon as I opened it, selected my network adapter (an LTE stick), it started showing me requests from ...
0
votes
1answer
34 views

How to learn the current network scheduler used in my linux machine?

How can I learn what network scheduler for packet selection is used in my linux system? Thanks!
0
votes
1answer
159 views

Is there a tool or website to generate DNS query packets for looking up the IP address of a hostname?

Is there a tool or web site where I can plug in some values and have it generate the bytes for a DNS query to look up the IP address of a hostname? Preferably one where it explains how the values ...
0
votes
2answers
5k views

Minimum size of the data part of TCP segment

My question has two parts: I know that the "data" part of an Ethernet frame can be 46~1500 bytes. Considering the IP header of 20 bytes + TCP header of 20 bytes, the minimum "data" size of a TCP ...
0
votes
1answer
9 views

Overlapping address error in Packet Tracer-Possible subnet error

I am working on my hands on final exam for Networking Fundamentals. I have accomplished everything except for putting the 4 devices on two separate subnets. These are my subnet calculations: Given ...
0
votes
1answer
35 views

calculate time taken to reach from network A to B without ping and telnet

I want to find distance between A and B either in terms of network time or Hops count.I have few ideas like I can ping B from A will log down time taken to respond that ping request . Also If I know ...
0
votes
2answers
74 views

What does a network packet consists of?

I know basic networking but I am not very good at it. Now I am calculating how many packets will be lost if I use UDP over IPv4. I can assume that the protocol overhead for data sent via UDP over IPv4 ...