Network traffic is one of most resource laden stream which contains everything we talk about on internet. If you can get data from it….you can know what is my password or even Google’s Password, in technical words its called as Network Sniffing and software which are used to sniff data are called as Packet Sniffers. SO if you place a sniffer on a router ( router is a hardware which sends data to right destination) you can see all the data and record it. Imagine the power of it now!!!

What is a packet sniffer ?

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A packet sniffer is a program which runs silently and monitors data on an network stream. Its called as passiveas it does not send any information to you but  just collects and stores it somewhere.If you run such a sniffer on your system, it can tell you your own ip  address and ip addresses of other sites which you visit.

How packet sniffers work ?

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Sniffers are basically small programs with one goal, interception of data. They can watch all unencrypted data that travels from your computer or when on router it can see all the data travelling through network. Now the question is howthey are allowed to read data. Its possible becuase of the architecture itself. See, our Ethernet or what is commonly called as "lan cards" are open connection. Which means, if you send some data I will read it but I will accept it only when the data is addressed to me.But now think, We have 4-5 computers in a network. You send a message to Computer A which is not having any sniffer. But Computer B is having one.  If you send some information  to computer A, the message is send ot everybody with IP address of Computer  A, so all the computers except A should reject it,  but I have one sniffer on Computer B. So though computer itself rejects it but the sniffer accepts the data.

Thus if you are sending unencrypted data on a network, there is a high chance of your data being stolen.

What are the types of packet sniffers ?

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• Commercial Sniffers which are used by network administrator to control the type and see the bottel neck data.
• Underground Sniffers which are used to steal data, so as to gain access of data stored which can be used for bad.

What are the uses of packet sniffers ?

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Packet Sniffers was never made to hack or stole information. They had a different goal, to make things secure. But then everything has a dark side. Here are few uses:-

• Network Analysis to find the traffic and its problem around the network.
• Detect Attackersif some resource is used high and traffic is coming from same ip again and again.
• Searching unencrypted text like password.
• To convert data into human readable format, mostly used in war to get hold of enemies.

Sniffers are very hard to detect due to its passiveness but there is always a way.This was the basic post on packet sniffers , think about it and we will continue our discussion in next post.