{"id":233,"date":"2015-04-27T14:16:08","date_gmt":"2015-04-27T14:16:08","guid":{"rendered":"http:\/\/betakb.veeble.org\/?p=233"},"modified":"2025-04-21T12:51:58","modified_gmt":"2025-04-21T07:21:58","slug":"bash-script-to-block-ips-during-a-ddos-attack","status":"publish","type":"post","link":"https:\/\/www.veeble.com\/kb\/bash-script-to-block-ips-during-a-ddos-attack\/","title":{"rendered":"Bash script to block IPs during a DDoS attack"},"content":{"rendered":"\n<p>We here discuss on Bash script to block IPs during DDoS attack. Use the below script to block IP addresses making too many connections.<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">#!\/bin\/bash\nif [ -e ip-list.txt ]\nthen\nrm -f ip-list.txt\nfi\nnetstat -tpn|grep&nbsp;:80|awk '{print $5}'|cut -d ':' -f 1|sort |uniq -c|sort -n -k 1|awk '{if ($1 &gt; 30) {print $2}}' &gt;&gt; ip-list.txt\nif [ -s ip-list.txt ]\nthen\nfor ip in $(cat ip-list.txt)\ndo\n\/usr\/sbin\/csf -d $ip &gt;\/dev\/null 2&gt;$1\ndone\nfi\n<\/pre>\n\n\n\n<p>Sometimes, Massive Ddos attacks cannot be stopped using a CSF firewall due to heavy connections in the short time period. In such cases, you need to &#8220;grep&#8221; the Attacking pattern from Domlogs and then block it via IPtables using the following script.<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">!\/bin\/bash\niplist=$(tail -5000 \/usr\/local\/apache\/domlogs\/domain.com |grep \"Pattern\" |awk '{print $1}' | sort -u)\nfor address in ${iplist}; do\niptables -I INPUT -p tcp -s ${_address} -j DROP\niptables -I INPUT -p udp -s ${_address} -j DROP\ndone\n<\/pre>\n\n\n\n<p>We highly recommend you to open a ticket via your <a class=\"external text\" href=\"https:\/\/secure.veeble.org\/accounts\/clientarea.php\" rel=\"nofollow noopener\" target=\"_blank\">Client Area<\/a>, whenever you see a DDOS attack.<\/p>\n\n\n\n<div style=\"height:25px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-uagb-call-to-action uagb-block-a1392f01 wp-block-button\"><div class=\"uagb-cta__wrap\"><h3 class=\"uagb-cta__title\">Unleash the Power of KVM VPS<\/h3><p class=\"uagb-cta__desc\">Experience lightning-fast performance and complete control with our cutting-edge KVM Virtual Private Servers. Built for speed and reliability.<\/p><\/div><div class=\"uagb-cta__buttons\"><a href=\"https:\/\/www.veeble.com\/in\/kvm-vps\/\" class=\"uagb-cta__button-link-wrapper wp-block-button__link\" target=\"_blank\" rel=\"noopener noreferrer\">Choose Your Plan<svg xmlns=\"https:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 512 512\"><path d=\"M504.3 273.6l-112.1 104c-6.992 6.484-17.18 8.218-25.94 4.406c-8.758-3.812-14.42-12.45-14.42-21.1L351.9 288H32C14.33 288 .0002 273.7 .0002 255.1S14.33 224 32 224h319.9l0-72c0-9.547 5.66-18.19 14.42-22c8.754-3.809 18.95-2.075 25.94 4.41l112.1 104C514.6 247.9 514.6 264.1 504.3 273.6z\"><\/path><\/svg><\/a><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>We here discuss on Bash script to block IPs during DDoS attack. Use the below script to block IP addresses making too many connections. [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":8629,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[13],"tags":[],"class_list":["post-233","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-scripts"],"uagb_featured_image_src":{"full":["https:\/\/www.veeble.com\/kb\/wp-content\/uploads\/2015\/04\/Bash-script-to-block-IPs-during-a-DDoS-attack.jpg",1366,768,false],"thumbnail":["https:\/\/www.veeble.com\/kb\/wp-content\/uploads\/2015\/04\/Bash-script-to-block-IPs-during-a-DDoS-attack-150x150.jpg",150,150,true],"medium":["https:\/\/www.veeble.com\/kb\/wp-content\/uploads\/2015\/04\/Bash-script-to-block-IPs-during-a-DDoS-attack-300x169.jpg",300,169,true],"medium_large":["https:\/\/www.veeble.com\/kb\/wp-content\/uploads\/2015\/04\/Bash-script-to-block-IPs-during-a-DDoS-attack-768x432.jpg",768,432,true],"large":["https:\/\/www.veeble.com\/kb\/wp-content\/uploads\/2015\/04\/Bash-script-to-block-IPs-during-a-DDoS-attack-1024x576.jpg",1024,576,true],"1536x1536":["https:\/\/www.veeble.com\/kb\/wp-content\/uploads\/2015\/04\/Bash-script-to-block-IPs-during-a-DDoS-attack.jpg",1366,768,false],"2048x2048":["https:\/\/www.veeble.com\/kb\/wp-content\/uploads\/2015\/04\/Bash-script-to-block-IPs-during-a-DDoS-attack.jpg",1366,768,false]},"uagb_author_info":{"display_name":"Digin Dominic","author_link":"https:\/\/www.veeble.com\/kb\/author\/digin-dominic\/"},"uagb_comment_info":0,"uagb_excerpt":"We here discuss on Bash script to block IPs during DDoS attack. Use the below script to block IP addresses making too many connections. [&hellip;]","_links":{"self":[{"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/posts\/233","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/comments?post=233"}],"version-history":[{"count":6,"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/posts\/233\/revisions"}],"predecessor-version":[{"id":8020,"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/posts\/233\/revisions\/8020"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/media\/8629"}],"wp:attachment":[{"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/media?parent=233"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/categories?post=233"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.veeble.com\/kb\/wp-json\/wp\/v2\/tags?post=233"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}