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...
           
           
           

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Raise again and again until lambs become Lion..

Never give up !!!!