how to deal with ddos attack

state of the Web server, just 17:50, the machine load increased sharply, basically can be determined, another round of attack began. First stopped the httpd, because has been unable to move, cannot. Then grab the bag, tcpdump-c 10000-i em0-n DST port >/root/pkts found a large number of datagram influx, filtered IP in it, no very centralized IP, and then suspected of being DDoS next based on the last suspic

How to check whether a Linux server is under DDOS Attack Address: http://www.phpthinking.com/archives/427 Log on to your server and run the following command as the root user to check whether your server is under DDOS Attack:Netstat-anp | grep 'tcp \ | udp' | awk '{print $5}' | cut-d:-f1 | sort | uniq-c | sort-nThis command displays the list of the maximum number

Course IntroductionContent of the lecture: Trends in DDoS attacks (scale, duration, and source) DDoS Attack protection Considerations (program, host system, and network device level) The use of CDN in cloud acceleration D Attack protection strategy and system using Cloud CDN (decision system, monitoring devic

The server is DDoS attack Defense shell script 1. Scripting Mkdir/root/bin vi/root/bin/dropip.sh #!/bin/bash /bin/netstat-na|grep Established|awk ' {print $} ' |awk-f: ' {print $} ' |sort|uniq-c|sort-rn|head-10|grep-v-e ' 192.168 |127.0′|awk ' {if ($2!=null $1>4) {print $}} ' >/tmp/dropip For I in $ (CAT/TMP/DROPIP) Todo /sbin/iptables-a input-s $i-j DROP echo "$i kill at ' Date '" >>/var/log/

programmer's fault, but the system itself is more of an error when it is implemented. Today, buffer overflow errors are constantly being found in Unix, Windows, routers, gateways, and other network devices, and constitute the largest and most significant number of security threats to the system. Recently, a design flaw known as buffer overflow (buffer overflow) is seriously endangering the security of the system and becoming a more headache problem than Y2K. Once this flaw is discovered by som

This article describes the DDoS attack solution for PHP. Share to everyone for your reference. The specific analysis is as follows: Today, one of their own machine suddenly send a large number of packets outside, can be more than 1G per second, although I use the strategy of UDP ban packet is not sent out but very occupy the cup Ah, so think of the last to find a way to solve. First look at the source cod

addresses in the dropip through iptables, and then write them to the log file/var/log/ddos. Another method is to use php to write ddos attacks and use other cloud platforms for operations. Sinaapp is used as the test object. Test method: create four versions of the app. The homepage code of version 1 is as follows: File_get_contents ('HTTP: // 2.mars.sinaapp.com/'); // version 1 triggers an

原文地址：http://www.phpthinking.com/archives/427 Log on to your server and execute the following command with the root user , using it you can check whether your server is in DDoS attack or not: netstat-anp |grep ' tcp\|udp ' | awk ' {print $} ' | Cut-d:-f1 | Sort | uniq-c | Sort–n This command will show that the logged on is the maximum number of IPs connected to the server List.

: 17:50 P.M.With the previous attack experience, I began to observe the status of the web server. at, the load of the machine increased sharply. I can basically confirm that another round of attacks started.First, stop httpd, because it has been unable to move. Then capture the packet. tcpdump-c 10000-I em0-n dst port 80>/root/pkts finds a large influx of data packets, filters out IP addresses, and does not have a very concentrated IP address, therefo

1, server-side analysis method (1) Synflood attack judgment A: Network Neighborhood-> the "Properties"-> double click the NIC, the number of packets received per second is greater than 500. B: Start-> program-> attachment-> command prompt->c:\>netstat–na and observe a large number of syn_received connection states. C: After the network cable plugged in, the server immediately solidified cannot operate, unplug sometimes can restore, sometimes need

security, you can set the maximum connection, single IP connection, and blacklist!Maximum connections:7000-> 30000 (LoginGate) is set to 40 single IP connection is set to: 207100-> 31000 (SelChrGate) is set to 30 single IP connection is set to: 207200-> 32000 (RunGate) is set to 1000 Single IP connection is set to: 20In this way, we can effectively prevent DDOS attacks or other variant attacks!Defends against SYN attacks!You can set an IP address seg

Today in order to rest, change the brain, so I found a previous collection of Python article, is about DDoS attack a script, just today is free, on the practice. Attached source pyddos.py: #!/usr/bin/env Python import socket import time import threading #Pressure Test,ddos Tool #---------------------------MAX _conn=20000 port=80 host= "www.baidu.com" page= "/ind

Brief description: SMS ddos Attack Vulnerability in Shanda online Detailed description: Shanda online will send a verification code to the mobile phone when the password is forgotten. URL: Http://pwd.sdo.com/ptinfo/safecenter/getpwd/ChgPwdStepOldPwd.aspx? Showbindmobile = 1 Mobile phone numbers can be controlled at will, and sms ddos attacks can be carried out wi

First of all, we used to attack the client and the server configuration method, using the most famous Redhat Linux for testing, this attack test I use Fedora CORE3, the software is the most famous DDoS attack tool Tfn2k Linux version, The attacked Windows Server system uses the Windows2000server service to open the APA

Site was DDoS attack, so wrote a foot to resist, to achieve the way: 1. Attack characteristics, different IP constantly post Web page, resulting in excessive resource consumption2. Analyze Nginx Access log, Judge post feature to obtain Client access IP3. Attack IP block with a connection number greater than 504. Recor

Introduction: On the network, the Linux server is a great way, but also the attack. This article will describe the NTP attack problem encountered in practice and the corresponding solution. 1. Scene description Aliyun on the ECS, over a period of time, frequent alarm, said the traffic is too large, the DDoS attack, the

PHP code malicious DDoS attack before I was touched once, the server resources are accounted for, so that the site can not be used properly, let me introduce the solution. Solutions Modify the php.ini file The code is as follows Copy Code "Disable_functions" changed to Gzinflate, the default is to vent"Allow_url_fopen" set to OffPhp_sockets.dll, open this module. The abo

Anti-DDoS script # Lightweight prevention against SYN AttacksIptables-N syn-floodIptables-A input-p tcp-syn-J syn-floodIptables-I syn-flood-P TCP-m limit-limit 3/s-limit-burst 6-J returnIptables-a syn-flood-J reject # Prevent too many Dos connections. You can allow up to 15 Initial connections from each IP address of the Internet Nic, exceeding the limit of discardingIptables-A input-I eth0-P TCP-syn-M connlimit-abve 15-J DropIptables-A input-p tcp-M

Log on to your server with the root user to execute the following command, using it you can check whether your server is in a DDoS attack or not:NETSTAT-ANP |grep ' tcp\|udp ' |awk ' {print $} ' |Cut-d:-f1 |Sort |uniq-c | Sort–nThis command displays a list of the maximum number of IPs that are logged on that are connected to the server.DDoS becomes more complex, as attackers use fewer connections, more IP-a

anomalous incursion based on illegal data. The barrier anomaly is based on anomalies that are not normally disposed of by warehouses (even if they are completely legal from a normative point of view). The famous "Ping of Death" is about the massive (but still legitimate) ICMP Echo solicitation packet. If the packet has the same source address, policy address and port, it is still legal, but it is harmful to the IP protocol stack. Stale land incursions have revitalized become imland and are dam