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“Possible SYN flooding” in log despite low number of SYN_RECV connections
Recently we had an apache server which was responding very slowly due to SYN flooding. The workaround for this was to enable tcp_syncookies (net.ipv4.tcp_syncookies=1 in /etc/sysctl.conf). I posted a...
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Protecting against UDP flood
One of my servers is being flooded with udp packets on random ports. 12:11:54.190442 IP 182.48.38.227.60173 > localhost.51523: UDP, length 1 12:11:54.190447 IP 182.48.38.227.60173 >...
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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...
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Amazon EC2 bandwidth charges in case of unwanted incoming traffic(ddos/flood)?
What happens if my EC2 instance gets ddosed/flooded, which could potentially go up to tens of gigabytes an hour(and even more) of undesired incoming traffic, will i be charged for this traffic? My...
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How can I prevent apache DoS flood?
I’ve configured a server running apache and a couple of days ago I noticed in the logs that there are bots running endless queries to the site. The logs show that those bots are running about 60...
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My server room has flooded
We recently went through a hurricane and our server room became flooded. Hooray for insurance. Anyway, I need to save as much data off one of the hard drives as possible. Yes, it was submerged for the...
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How to avoid floods like this?
Instead of describing what’s happening I’ll post a screenshot of Apache’s server-status page: Screenshot It is a Nigerian IP. I’m having this problem for years now and I never found a viable solution...
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How to remove route with IP?
Used to ban some flood-bots with route add -host $ip reject But couple of ‘good’ IPs were banned as well. My question is stupid (but I’ve searched and found no good solution (all were large and/or...
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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...
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apache being flooded?
I have a linux apache server which was running fine until a few days ago. What happened is from the access log there are lines like this, and the log file is growing by many lines every second....
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