Distributed Denial Of Service (DDOS) is the intentional paralyzing of a computer network by flooding it with data sent simultaneously from many individual computers (so-called zombies) which are used to stage DDOS attacks

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How much does it cost to protect your website against DDOS, by tier?

Cross-posted to Quora Today several financial institutes in Israel (banks, stock exchange) were DDOSed. They decided to block all foreign IPs as a first aid measure. While I agree that it was ...
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My server is used for DDoS attacks

I have webserver (centos + cpanel), and one of the clients used my server for DDoS-ing, how can I identify that client/user? What logs should I look to, is there any settings I can modify so such ...
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How is a ddos simulation any different from a real attack?

I asked a question earlier today on serverfault, but found out that there was also a security stack exchange. I had conflicting answers from there. The following is the link: ...
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what is the Akamai Name Server i see at some big companies

I have played with DNS a lot lately, and i have found that some big companies's web sites uses the Akamai NS as the Name Server for thier WWW servers, for example: $>nslookup > www.redhat.com ...
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How are server overload and DoS/DDos different?

I know that server overloads are caused due to excessive number of genuine requests and DoS due to malicious request. But, my question is, if you have designed a system for Overload mitigation, does ...
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I'm having a DDoS attack, my hosting company is stupid, and I need to know what is hapening

So ok, right now my windows 2003 dedicated server is under attack by some guy who's flooding UDP packets (~90.000 packets/sec) on my 100Mbps server for the last 8 hours. I'm on a shared port, so I'm ...
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How to simulate DDoS attacks from the Internet?

The idea behind security tests is easy. You want to know what a hacker can do - you hire a security expert who acts like a hacker to see how far he can get. You want to know what an evil admin can do ...
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Accessing a site (which is) under a DDoS

Lets say http://www.an-example-site.com is under DDoS attack. Alice, who does not have direct access to the hardware infrastructure, urgently wants some information which can be accessed through the ...
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Could Stock Exchange be shut down by HFT attack vector?

First of all, stock, not stack exchange. I just read this post on Krypt3ia. In short, it says that HFT attack vector in combination with DDoS is possible new nemesis for stock exchange IT systems. ...
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Looking for botnet IP address feeds to protect against DDoS

I would like to get a live feed of botnet IP addresses delivered from a service and block them under certain conditions. Preferably community based/open source but open to looking at worthy commercial ...
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How do DoS/DDoS work?

In the last days one could frequently read about attacks from anonymous and LulzSec against different platforms like Sony or HBGary etc. Yesterday for example they DDoS'ed soca.gov.uk and jhw.gov.cn. ...
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what is a good public available iptables script for ddos mitigation?

what is a good public available iptables script for ddos mitigation?
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Reject IP packets with an ICMP error, or just drop them?

Consider an internet-facing host (the outer firewall). What should be done with undesired traffic: just drop it, or send back an ICMP error such as port unreachable? (In Linux terms: iptables -P DROP ...
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High concentration of UDP traffic, good or bad?

Should a network have a high concentration of UDP traffic compared to TCP traffic bad for a network especially in the context of network security? I'm looking at my organization's network protocol ...
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How to make a report after a ddos attack? what information do I need to write on the report?

In my company, after a DDOS against a server, my employer asked me to make an analysis of the attack and to write down some stuff. What do you think I need to write down in my report? Is there any ...
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Why is it difficult to catch “Anonymous” or “Lulzsec” (groups)?

I'm not security literate, and if I was, I probably wouldn't be asking this question. As a regular tech news follower, I'm really surprised by the outrage of Anonymous (hacker group), but as a ...
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How to test against DDoS in a controlled enviroment?

Can you suggest me methods or tools that can help in simulating a DDoS attack in a controlled enviroment (like my private lab)?
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How can a Software application defend against DoS or DDoS?

Most of the solutions for DoS attacks are not at the application level. In case I am using a proxy server, what are the possible countermeasures for DoS at the application level?
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What techniques do advanced firewalls use to protect againt DoS/DDoS?

It is hard to protect a server against Denial of Service attacks, DoS/DDoS. The two simple ways I can think of is to use a server with much resources (e.g. CPU and memory), and to build the server ...