37
votes
6answers
45k views

How can I prevent a DDOS attack on Amazon EC2?

One of the servers I use is hosted on the Amazon EC2 cloud. Every few months we appear to have a DDOS attack on this sever. This slows the server down incredibly. After around 30 minutes, and ...
10
votes
3answers
541 views

Dealing with NTP reflection attacks in IPTables

We're dealing with an NTP reflection / amplification attack at our colocated servers. This question is specific to responding to NTP reflection attacks, and not directed at DDoS in general. Here's ...
10
votes
6answers
721 views

DDoS. Are we that helpless? [duplicate]

With recent DDoS incidents related to wikileaks, I can't help but feel that pretty much all sites online are very vulnerable to such attacks. Visa, MasterCard (to name a few) have shut down because of ...
9
votes
8answers
18k views

How to prevent a LOIC (DDOS) attack? [duplicate]

The program LOIC (in the news a lot the last days) causes a lot of damage. What can I do on my server to prevent this kind of attacks? Auto-block ip when receive a strange connection? Because mostly ...
8
votes
2answers
17k views

Too many TIME_WAIT state connections! [duplicate]

I've been reading about this everywhere all day, and from what I've gathered, TIME_WAIT is a relatively harmless state. It's supposed to be harmless even when there's too many. But if they're jumping ...
6
votes
5answers
2k views

DDoS Protection Services - are they good enough? [duplicate]

first of all, I understand that it's better to have DDoS protections on data center level. But our DC is not ready to provide good quality of protection. So we thinking about using some external DDoS ...
5
votes
4answers
3k views

Mitigate DDoS attack with HAProxy [duplicate]

We were targeted earlier today by a DDoS attack. There was 20x as many connections as normal on our load balancer (HAProxy), and all the backend nodes continued to go down during this attack. System ...
5
votes
2answers
1k views

DDOS attack - How to prevent [duplicate]

Recently I read about Denial of Service attack on Amazon & PayPal. I am curious that how this is performed. These big companies must have huge servers, so DOS would require billions of bots to ...
4
votes
3answers
880 views

100mb/s upgrade to 1gbps network - To Prevent DDOS [duplicate]

I have been under constant DDOS attack the last couple of weeks. Now it seems my servers network is being flooded till it just doesn't have space anymore to receive and send normal packages. I run ...
4
votes
3answers
3k views

DDOS using ntp server

I've heard about new kind of DDOS where ntp is used for reflection . My questions are really simple : Can you please give details on how they work and clarify? Since ntp is ran over UDP, I suppose ...
4
votes
6answers
3k views

How to survive anonymous DDOS attack? [duplicate]

Every time the anonymous group targets a website, they are able to take it down.. even for large corporates / governments with professional. I read (basic theory) about dealing with normal DDOS ...
4
votes
2answers
149 views

Will MX records with a longer TTL help mitigate effects of DoS attack? [duplicate]

We have our email hosted at Google Apps, and have our DNS servers for the domain setup at Namecheap. About a month ago our website went down (not a big deal, since it's most just a contact info page),...
4
votes
2answers
519 views

How to prevent DDoS attacks? [duplicate]

I am a creator of a flash game server. I use cloudflare for my site, however the game tcp server cant be protected by CloudFlare. For about 2 months some person DDoSes my game using direct ip. Every ...
4
votes
3answers
1k views

In Linux, does using route to blackhole an IP result in better performance than dropping in iptables? [duplicate]

During a DDOS attack, if we are finding IPs we want to block will we see better performance using a null route as opposed to iptables? Null routing we would do something like: ip route add blackhole ...
4
votes
2answers
7k views

How Can I Harden the TCP/IP Stack in Windows Server 2008? [duplicate]

I would like to make sure that my Windows 2008 servers are hardened against DDOS attacks. There is a Microsoft Technet article on Hardening the TCP/IP stack, but it was last revised in January 2006. ...

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