3
votes
2answers
240 views

Blocking incoming traffic from privileged port (< 1024) to mitigate DNS DDos Amplification attacks

Hope someone can clarify. As I understand, in a DNS DDos Amplification attacks Multiple DNS queries are sent to a vulnerable name server with the source IP spoofed to that of the target server. The ...
0
votes
1answer
627 views

What is the difference between SYN cookie, SYN cache, and SYN proxy?

I am trying to understand some techniques regarding SYN flood prevention and there are three terms I couldn't find a clear explanation of. The terms that are confusing me are: SYN Proxy SYN Cache ...
4
votes
3answers
3k views

How to protect myself against paid DDoS services?

I am domestic user and I am getting attacked regularly by a guy that hates me. Here is the background story: that guy uses Skype resolvers (tools offered by paid DDoS services) to find out my IP ...
2
votes
2answers
3k views

IPTables DDoS protection working with per client IP address counter AND UDP

I am looking to protect LAMP server with a software, which will detect above average number of requests from single IP numbers (in this case DNS queries), and add these hosts to IPTables deny chain. ...
-2
votes
1answer
670 views

Linux tools to choose suitable Cisco ASA 5500

I have a linux webhosting server which affects a high DDOS. I want to use Cisco ASA 5500 Series Adaptive Security Appliances to protect the linux server from this DDOS. I know there are many factors ...
7
votes
5answers
9k views

How to trace a DDOS attack on a dedicated server and block it?

I have a dedicated server and I'm hosting a game, and the web page (using Apache) for account registering. The server is being ddosed since 8 months ago till today. I've tried to talk with the server ...
6
votes
4answers
2k views

Block all BotNets and TOR addresses from accessing our site

I've heard that many DOS attacks and general "black hat hacking" attempts occur over the TOR network. Is it possible for me to dynamically block source IP's by their presence in a BotNet or similar ...
2
votes
1answer
1k views

How should I configure a Citrix Netscaler to protect against HTTP, TCP, or UDP flood attacks?

I have a Citrix Netscaler and want to configure the appliance appropriately so that it can protect my hosts from a DDOS. Is this something I can do here, or must I take action on the host itself?
5
votes
1answer
773 views

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 ...
4
votes
4answers
1k views

what is a good public available iptables script for ddos mitigation?

what is a good public available iptables script for ddos mitigation?
12
votes
2answers
3k views

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 ...
39
votes
6answers
11k views

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 ...