SYN flooding still a threat to servers?

Posted by Rob on Server Fault See other posts from Server Fault or by Rob
Published on 2010-05-14T17:11:44Z Indexed on 2010/05/16 4:40 UTC
Read the original article Hit count: 331

Filed under:

python

|

tcp

|

syn-packet

|

rst-packet

|

denial-of-service

Well recently I've been reading about different Denial of Service methods. One method that kind of stuck out was SYN flooding. I'm a member of some not-so-nice forums, and someone was selling a python script that would DoS a server using SYN packets with a spoofed IP address.

However, if you sent a SYN packet to a server, with a spoofed IP address, the target server would return the SYN/ACK packet to the host that was spoofed. In which case, wouldn't the spoofed host return an RST packet, thus negating the 75 second long-wait, and ultimately failing in its attempt to DoS the server?

© Server Fault or respective owner

Related posts about python

unmet dependencies in Ubuntu 12.04

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried today to install a dvb-card on my Ubuntu 12.04 (Linux blauhai-linux 3.2.0-25-generic #40-Ubuntu SMP Wed May 23 20:30:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux ). The installation failed with an error. After that, i tried to install python (it was already installed but i got this error): linux:~$… >>> More
How can I get sikuli-ide to work?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I installed sikuli-ide with sudo apt-get install sikuli-ide Everything was fine until I tried to start it from the terminal. I typed sikuli-ide But the only response I got was [info] locale: en_US The application was not started, furthermore there is no desktop file and sikuli-ide does not… >>> More
Getting PATH right for python after MacPorts install

as seen on Super User - Search for 'Super User'
I can't import some python libraries (PIL, psycopg2) that I just installed with MacPorts. I looked through these forums, and tried to adjust my PATH variable in $HOME/.bash_profile in order to fix this but it did not work. I added the location of PIL and psycopg2 to PATH. I know that Terminal is… >>> More
call python with system() in R to run a python script emulating the python console

as seen on Stack Overflow - Search for 'Stack Overflow'
I want to pass a chunk of Python code to Python in R with something like system('python ...'), and I'm wondering if there is an easy way to emulate the python console in this case. For example, suppose the code is "print 'hello world'", how can I get the output like this in R? >>> print… >>> More
Python - Calling a non python program from python?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am currently struggling to call a non python program from a python script. I have a ~1000 files that when passed through this C++ program will generate ~1000 outputs. Each output file must have a distinct name. The command I wish to run is of the form: program_name -input -output -o1 -o2… >>> More

Related posts about tcp

TCP RST Reset Every 5 Minutes on Windows 2003 sp2

as seen on Server Fault - Search for 'Server Fault'
Hey, Recently I had a web developer come to me and ask why he was receiving connection errors in his app that was accessing a sql database. So, I went through my normal trouble shooting steps to isolate or reproduce the issue. I discovered that if I connected to the database using Query Analyzer… >>> More
iptables issue on plesk

as seen on Server Fault - Search for 'Server Fault'
i don't know how to open a specific port (rtmp=1935) on my CentOS server using Plesk or itables. I created new rules for port 1935 i/o using Plesk/Modules/Firewall but this doesn't work. Nmap scanning tells me this : 1935/tcp filtered rtmp . So i decided to have look at my iptable using SSH (iptables… >>> More
Httpd problem, suspect an attack but not sure

as seen on Server Fault - Search for 'Server Fault'
On one of my servers when I type netstat -n I get a huge output, something like 400 entries for httpd. The bandwidth on the server isn't high, so I'm confused as to what's causing it. I'm suspecting an attack, but not sure. Intermittently, the web server will stop responding. When this happens… >>> More
Why can blocked IPs get through my iptables? What's wrong with this configuration?

as seen on Server Fault - Search for 'Server Fault'
(Why can/How are) blocked IPs (get/getting) through my iptables? Hello and thanks for your consideration... I have configured iptables and included (below) output from the command "iptables --line-numbers -n -L" yet IP addresses (like 31.41.219.180) from IP blocks I have already blocked are getting… >>> More
iptables syn flood countermeasure

as seen on Server Fault - Search for 'Server Fault'
I'm trying to adjust my iptables firewall to increase the security of my server, and I found something a bit problematic here : I have to set INPUT policy to ACCEPT and, in addition, to have a rule saying iptables -I INPUT -i eth0 -j ACCEPT. Here comes my script (launched manually for tests) : #… >>> More