Creating Broadcast storms to take down a switched Network?

I am willing to Take down a LAN Network with Broadcast storms,

Before that here is the topology of our overall Network





Please have a look at the following image which will represent The network set-up i am talking,

Code:

http://i54.tinypic.com/a32fzn.png
(As the image is large ,I am placing this in code instead of [IMG] tags)



And here is the Information about our LAN 

 Total sub-nets-4



clients-90% of them running windows xp-sp2 and rest running windows 7 and vista.



Servers-each sub-net has a DC i.e server,they are running windows 2003 OS.



Main-server-i.e the 1 that is providing internet access to rest of the
clients and other servers in sub-net 1,2,3,4 running red-hat linux.



And switches used in our networks are un-managed one and our network
does not have any kind of NIDS,HIDS,NIPS,HIPS or any kind of Network
security set-up,..



Traffic or accessing pc's across sub-nets is allowed by the Domain controller,



And LAN or Ethernet speed in a single sub-net is  100 mbps

I am having access in
one of the pc's in sub-net 1 and i have privilege to install
Applications and i am willing to create some kind of Broad-cast storms
to bring down All the sub-nets,I don't know how much traffic i need to
generate to take down this network,Also i am not sure about the right
protocol's and exact Attacking vector to choose ,I heard about ARP
broad-cast storms,but i am not sure about

generating ARP broad-cast across sub-net's ,Also i am not sure about the
switch type,because it is kind of OLD and it is a un-managed one with
no-IP Address for it..



So looking for some ideas and help,hope i will find some help...
           
           
           

---

Raise again and again until lambs become Lion..

Never give up !!!!

           
               

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Network Sniffing- An Introduction

Do you think that you are safe by using some smart antivirus tools to protect your computer from backdoors like remote administrator tools or from keyloggers, it is good to use smart antivirus and firewall but you must consider sniffing as a security issue. There are so many tools available for various operating system includes windows and Linux, we will talk about the tools later on but firstly there is a need to describe sniffing.  

Network sniffing tools and packet analyser tools are generally the same thing, the main purpose of sniffing is to analyse the incoming and outgoing packets, keep in mind when you connect to a web server or to any network (computer) you sends your data via wired connection or wireless connection in the form of packets, your data goes in the form of packets.


A packet contain the source (Sender) and the destination (Receiver) IP and MAC address and also it contains the data that are going to be sent. So just imagine if someone get this packet than he/she can easily know what you have send, an attacker can easily sniff your confidential information (credit card, paypal, passwords etc), so the sniffing is the important attack that should be consider as a security measure.



Large organisation and web server uses secure connection for transmission for example paypal uses https:// instead of http:// so its means your data goes in the form of encrypt data. If you are using SSL it does not mean that you are secure ever there is way to crack the secure channel


All the thing that discussed above shows that sniffing is not a good thing, however it is not true the Positive usage of sniffer is also its regular usage, which aim is to maintain network and system working normally.

• Capturing packets
• Recording and analysing traffic
• Decrypting packets and displaying in clear text
• Converting data to readable format
• Showing relevant information like IP, protocol, host or server name and so on.

While the negative usage is open and clear:

• Catching password, which is the main reason for most illegal uses of sniffing tool
• Capturing special and private information of transactions, like username, credit ID, account, and password
• Recording email or instant message and resuming its content
  

The famous and the most widely used tools for sniffing purposes are:

• Wireshark (We will discuss it on later)
• Kismet   (For wireless sniffing, discussed)
• Netstumber (For wireless sniffing, discussed)
• Kismac (For Wireless sniffing, discussed)
• Ettercap (We will discuss it on later)
• Tcpdump ( We will discuss it on later)
• Cain and Abel ( We will discuss it on later)
• Etc

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