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VPS server hosts suspect DOS attack if PPS is too high. This limits packets at the interface level. Do "sudo apt-get install iptables-persistent" to make persistent, or, if you already have, reconfigure with "sudo dpkg-reconfigure iptables-persistent"
This will highlight (with a box over it) any changes since the last refresh.
Then you can remove the specific entry:
iptables -D INPUT 10
Just make sure these are set:
Else your changes won't stick when you restart iptables.
These series of commands allows you all at once to make a backup of your current config, edit that config, then saves it as the running config and makes it persistent. I would advise knowing what your doing to the config before running this because if you mess up say the port 22 portion, you may get knocked off the system. ;) Don't say I didn't warn ya!
this alternative shows the differences as they occur so that they are made plain
Rather then editing the /etc/sysconfig/iptables file, or during a kickstart doing some awk/sed magic, easily add a rule in the correct place within iptables
This command will open tcp port 3000 in your machine
If you changed the default policy on any chain other than filter table chain's, this won't be enough.
To save all rules so that they are not lost in case of a server reboot:
Should run with sudo
Ddos syn attack
Takes IP from web logs and pipes to iptables, use grep to white list IPs.. use if a particular file is getting requested by many different addresses.
Sure, its already down pipe and you bandwidth may suffer but that isnt the concern. This one liner saved me from all the traffic hitting the server a second time, reconfigure your system so your system will work like blog-post-1.php or the similar so legitimate users can continue working while the botnet kills itself.
Clear iptables rules safely
a simple command in order to make iptables rules permanent, run @ sudo!
Destination IPs will become invisible to source IPs!
Safe for whitespaces in names.
show your current iptable rules from every available iptable table
I was previously unaware of the -v switch. As a result I never got specifics about which interfaces the allowed or dropped applied to. Thought I'd share the wealth...
FYI, -n prevents DNS resolving of IPs.
Retrieve top ip threats from http://isc.sans.org/sources.html and add them into iptables output chain.