Hi, 1. Switch Flooding We have a nice problem in our organisation. Due to viruses, some windows machine or the other starts flooding the network with packets. And, in the end, one of our switches comes down making us to manually restart the switch. I don't (intuitively) see how iptables can help in this scenario.... But, I want to know whether any solution exists to this? If I make all the machine's gateway as a linux system, and rate limit the packets there will it help? 2. Chain traversal Why is this chain traversal looking complicated? if there is atleast one rule in every inbuilt chain, it seems that there are many possible permutations of the chain traversal. How do you guys manage with it?