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Questions tagged [flooding]

73 questions
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IPTABLES for block sync flood over udp

I'm a victim of a sync flood attack over UDP port. This came from a lot of different IPs. The machine, a dedicated server, is an hlds game server, and the attacker overload the UDP ports, this cause a big trouble in the game, with packet loss and…
Kiwi
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The more secure iptables script imaginable. Does one exist?

I plan on buying a server soon. I'd like the server to be as secure as possible, only having POP3, SMTP, SSH and HTTP open. I know how to write an iptables script to only allow those connections and drop everything else, but I have no clue how to…
Simon
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How shared hosted web servers deal with spam (flood) attacks?

I want to know how shared webhosting or other types of it deal with Spam issues. Example: stop serving the website for a period of time, and how much is it? ...
BlzOfHK
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Why does ping flooding a domain name freezes and not a direct ip address

I am wondering why, when ping flooding a domain, the ping flood freezes after a couple of seconds then continues and this freeze, unfreeze continues until i stop the ping flood. When i do the same using the ip it does not freeze. NEVER. i did for…
Luis Alvarado
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SYN flooding, kernel error

My server (http://monitor.wingify.com/munin/visualwebsiteoptimizer.com/app.visualwebsiteoptimizer.com.html) recently had an outrage. One of the suspecious things I found was loads of SYN flooding messages in /var/log/messages Feb 8 15:17:34 app…
Sparsh Gupta
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5 answers

TCP attack invisible to netstat

we are hit by a strange attack, the attacker even emailed to challenge us. The output of "netstat -n" is just a few "ESTABLISHED" and "TIME_WAIT" typically, yet the server's website cannot be reached from outside. And when typing "ssh 127.0.0.1" on…
Joe
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How does ospf control flooding?

What method is used by ospf protocol to prevent looping of flooded packets for link state advertisements? The packet header does not contain any timestamp. How do the routers recognize that it is the same advertisement that they sent…
Rohit Banga
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Automatic TCP SYN - cookie activation

I am simulating a SYN flood attack on a Raspberry Pi 1 with KALI Linux (ARM) installed. A similar message as mentioned in this post was printed after performing the attack: How to avoid syn cookies. kernel: possible SYN flooding on port X. Sending…
Gerry
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How to detect an intranet SYN flood?

I got this problem: whenever I plug a Linux-server into the intranet, the whole network slows down and then die. Every ping/ssh connection between the intranet yields time out. I unplugged it, then everything came back to normal. Searching around…
EyeQ Tech
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Running tcpdump starts ssh flood

I have runtime Linux running in a PLC. My development machine is running Ubuntu 14.04. The PLC and the development machine are connected through a five port switch. I ssh to PLC from my development machine to transfer executable of a networking…
awatan
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Apache being hit by requests (cpu 100%)

recently we moved to a new host (DO) for one of my client after being on a shared account . I was monitoring the cpu and it was always at 100% , knowing that the site dosnt get a lot of traffic , decided to check the access log and i saw the…
Tarek
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1 answer

can't block IP that is attacking one of my sites with xmlrpc.php attack

I'm at my wits end right now. I have a wordpress site that thankfull is still just a blank template. Last week I saw it was being hammered by an IP 185.130.5.180 from Lithuania and has been flagged multiple times for spamming. I can't seem to block…
Tamerax
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Why is there flooding on L2 but not on L3?

Why is it, that on L2 (when there is no MAC Table entry for a new packet) there is MAC Flooding. But at the same time on L3 there is an ARP request (when there is no entry in the ARP table for a new packet) and no flooding?
Jimmy88
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