{"id":19371,"date":"2026-02-23T11:25:37","date_gmt":"2026-02-23T11:25:37","guid":{"rendered":"https:\/\/iprovpn.com\/resources\/?p=19371"},"modified":"2026-02-23T11:25:37","modified_gmt":"2026-02-23T11:25:37","slug":"what-does-a-firewall-do","status":"publish","type":"post","link":"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/","title":{"rendered":"What Does a Firewall Do?"},"content":{"rendered":"<p><span style=\"font-weight: 400\">Germany is a leader in technology and industry across Europe. From busy factories in Bavaria to finance centers in Frankfurt, German companies handle large amounts of important data every day. But more connections mean bigger risks. The German Federal Office for Information Security (BSI) says the IT security situation is tense.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400\">Every day, hundreds of thousands of new malware appear. In this setting, it is very important to understand what a firewall does and the fungsi firewall, the main jobs it performs to protect networks. This matters for German businesses, government offices, and regular users.<\/span><\/p>\n<p><span style=\"font-weight: 400\">        <div class=\"iprovpn_btn_cta_row\">\n    \t<a class=\"btn_cta\" href=\"https:\/\/iprovpn.com\/buy-vpn\" title=\"Get iProVPN Now\">Get iProVPN NOW <i class=\"fas fa-long-arrow-alt-right\"><\/i><\/a>\n    \t<\/div>\n    <\/span><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_75 ez-toc-wrap-center counter-flat ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<div class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/div>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #000000;color:#000000\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #000000;color:#000000\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#The_Simple_Basics_of_Firewalls_and_Fungsi_Firewall_in_Germany\" >The Simple Basics of Firewalls and Fungsi Firewall in Germany<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#How_Firewalls_Work\" >How Firewalls Work<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#Different_Types_of_Firewalls_and_How_They_Are_Used_in_German_Industries\" >Different Types of Firewalls and How They Are Used in German Industries<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#Why_Fungsi_Firewall_Is_So_Important_for_German_Business_and_Critical_Systems\" >Why Fungsi Firewall Is So Important for German Business and Critical Systems<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#FAQs\" >FAQs<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#What_is_the_main_fungsi_firewall_for_protecting_important_systems_in_Germany\" >What is the main fungsi firewall for protecting important systems in Germany?<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#How_does_the_new_NIS2_rule_through_BSI_law_change_firewall_needs_for_German_companies\" >How does the new NIS2 rule through BSI law change firewall needs for German companies?<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#Are_strong_firewalls_easy_to_buy_and_use_for_small_companies_in_Germany\" >Are strong firewalls easy to buy and use for small companies in Germany?<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#Which_firewall_types_does_BSI_suggest_and_why\" >Which firewall types does BSI suggest and why?<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#How_does_the_fungsi_firewall_help_follow_GDPR_and_BDSG_rules_in_German_groups\" >How does the fungsi firewall help follow GDPR and BDSG rules in German groups?<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#Final_Words\" >Final Words!<\/a><\/li><li class='ez-toc-page-1'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/iprovpn.com\/resources\/what-does-a-firewall-do\/#Start_Browsing_Privately\" >Start Browsing Privately!<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"The_Simple_Basics_of_Firewalls_and_Fungsi_Firewall_in_Germany\"><\/span>The Simple Basics of Firewalls and Fungsi Firewall in Germany<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400\">A firewall is a security tool for networks. It can be a hardware box, software on a computer, or a service in the cloud. It creates a wall between safe inside networks and unsafe outside ones, like the internet. The fungsi firewall includes watching data packets, following access rules, keeping records, and stopping threats at the edge.<\/span><\/p>\n<p><span style=\"font-weight: 400\">In Germany, the BSI tells companies to use this edge defense. Instead of protecting every single device, put firewalls at the main entry points to guard the whole network. BSI advice for regular users says firewalls check data packets by their IP addresses. They let only safe traffic through and stop anything that looks risky. This matches Germany\u2019s way of using many layers of protection, called defense in depth. It is used in important areas like energy, transport, and health care.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Firewalls started in the late 1980s in the United States. But in Germany, they became common in the 1990s when internet use grew after reunification. Today, German-made tools like Securepoint UTM firewalls from L\u00fcneburg and the open source IPFire from Datteln show local smart ideas. These tools show the fungsi firewall by mixing basic packet checking with extra features that fit EU rules.<\/span><\/p>\n<p><span style=\"font-weight: 400\">The fungsi firewall does more than just block. It uses stateful inspection. This means it remembers the state of connections and lets real replies come back while dropping requests that come from nowhere. In Germany\u2019s export economy, where data crosses borders all the time, this keeps talks with EU partners safe and reduces spying from advanced threat groups. BSI says 22 such groups targeted Germany lately.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Personal firewalls on single devices add one more layer. They are useful for Germany\u2019s many home office workers after the pandemic. These run on the device itself and watch outgoing connections to stop spyware from sending data out. BSI says to use them together with regular updates, virus scanners, and rule checks. This fits Germany\u2019s careful and exact way of working.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_Firewalls_Work\"><\/span>How Firewalls Work<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400\">To understand what a firewall does, look at how it really operates. These steps form the firewall function. Firewalls check traffic at different layers of the network model, from basic packet rules at layers 3 and 4 to full checks at the application layer.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Basic packet filtering is the start of the fungsi firewall. It looks at packet headers for source and destination IP, port numbers, and protocols. A rule may allow normal web traffic on port 80 from trusted German IP ranges and block all else. In a Siemens factory, this stops unwanted entry to control systems.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Stateful inspection makes the firewall smarter. It tracks if a connection was started from inside. For example, if a German user asks for data from a supplier, the firewall lets the answer come back. Any request from outside that was not asked for gets dropped. This helps against DDoS attacks that often hit public offices in Germany during tense times.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Next-generation firewalls are used by big German companies like Deutsche Telekom or Allianz. They add smart features: they know which app is sending data, link to user names, and use threat info from the web. They check inside the data for virus signs or strange actions and work with BSI suggested prevention systems.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Proxy firewalls work at the top layer. They stop the connection, check the full content, and start a new safe one. This is good for protecting secret government data or bank deals in Frankfurt. BSI rules for high security need either basic packet filters or full proxy types.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Cloud firewalls fit Germany\u2019s growing use of cloud services under the Gaia-X plan for European data control. These services keep all data in German or EU centers to meet BDSG and GDPR rules on where data can be stored.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Keeping logs and sending alerts is another key part of the firewall&#8217;s function. Modern tools create clear records for later checks. This is needed under NIS2 rules that now cover about 29,000 groups in Germany. The BSI law makes security a top priority for company leaders, with personal risk if rules are broken.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Setting up a firewall in Germany follows BSI tips: use only needed rules, close unused ports like RDP port 3389 that ransomware likes, turn on safe testing for doubtful files, and check logs often. Some personal firewalls learn by themselves, but experts say not to trust them fully because wrong settings can happen.<\/span><\/p>\n<p><span style=\"font-weight: 400\">German tools do well here. Securepoint\u2019s system is built fully in Germany with local servers and gives GDPR safe firewalls with no hidden doors. This is liked by government offices that avoid foreign tools. IPFire from Datteln is open source and adds easy VPN and blocking by country to help users stop traffic from risky places.<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Different_Types_of_Firewalls_and_How_They_Are_Used_in_German_Industries\"><\/span>Different Types of Firewalls and How They Are Used in German Industries<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400\">Germany\u2019s many industries need different kinds of fungsi firewall setups. Hardware firewalls are strong boxes from companies like Securepoint or others with a good presence in Germany. They give fast protection at the outer edge for factories. Siemens uses them to separate factory control networks from office networks so problems cannot spread.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Software firewalls run on computers or servers. They include the one in Windows or Linux tools, improved by IPFire. They are good for virtual servers that hold patient data in hospitals that must follow critical system rules.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Cloud firewalls grow as needed and suit German firms that use many online services. They keep the speed high and store data only in German centers.<\/span><\/p>\n<p><span style=\"font-weight: 400\">All-in-one security boxes mix a firewall, virus check, VPN, and web filter. German small companies like these because they are simple. Securepoint products win awards and are made in Germany, so they meet data rules easily. Next-generation firewalls are the main choice for big firms. They use learning systems for zero-trust models, set rules by user job, and connect to endpoint tools. In banks watched by BaFin, they help keep rules and react fast to problems.<\/span><\/p>\n<p><span style=\"font-weight: 400\">For government and secret work, BSI-approved firewalls follow special profiles to protect high-level data.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Open source like IPFire is used by schools and small cities because it is free to check and gets fast community updates. This fits Germany\u2019s support for its own tech.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Many places now mix types. A main hardware firewall guards the center, while software protects the ends, and cloud parts handle remote workers.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Each type helps the firewall function in its own way. But good results need a correct setup. BSI tips say test often, divide networks, and use extra login steps with firewalls. In recent ransomware cases on cities, groups with good divided firewall rules lost much less than those with open networks.<\/span><\/p>\n<p><span style=\"font-weight: 400\">German firms like SAP set special firewall rules in their software to guard supply chains. Car makers use them for safe car-to-car talk. The result is a stronger defense in a country that is often targeted by state-level cyber attacks.<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Why_Fungsi_Firewall_Is_So_Important_for_German_Business_and_Critical_Systems\"><\/span>Why Fungsi Firewall Is So Important for German Business and Critical Systems<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400\">Germany has Europe\u2019s biggest economy and moves huge amounts of data every day. The firewall directly reduces risks shown in BSI reports: professional ransomware, new unknown attacks, and DDoS attacks used in politics.<\/span><\/p>\n<p><span style=\"font-weight: 400\">By setting clear borders, firewalls stop the first entry that starts most breaches. In energy, they keep control systems separate from office networks to avoid power cuts from outside attacks. BSI numbers show edge attacks are still the favorite against German targets.<\/span><\/p>\n<p><span style=\"font-weight: 400\">For companies, the firewall function saves money by reducing downtime, eliminating ransom payments, and securing better insurance deals. Insurance firms often ask for modern firewalls to give lower prices. This matters because many German companies see cyber attacks as a real danger to their future.<\/span><\/p>\n<p><span style=\"font-weight: 400\">In health care, firewalls guard patient records under strict laws and allow safe online doctor visits while stopping trick emails that could leak millions of records. Factories stop theft of designs and keep Germany\u2019s lead in exact machines.<\/span><\/p>\n<p><span style=\"font-weight: 400\">City offices, often hit by ransomware, use firewalls to keep public services separate from admin systems. After the new NIS2 rules, with 24-hour report times for big events, fast firewall alerts help provide quick answers.<\/span><\/p>\n<p><span style=\"font-weight: 400\">The firewall also stops inside leaks by checking outgoing data. With extra data protection tools, it meets GDPR needs and avoids big fines up to 4 percent of world sales.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Germany\u2019s answer is a full approach: firewalls plus training, updates, and backups. Police actions against crime networks also help the technical side.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"FAQs\"><\/span>FAQs<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400\">\n<div class=\"blog_faq\">\n                <div class=\"faq\">\n            <h3 class=\"faq_title\"><span class=\"ez-toc-section\" id=\"What_is_the_main_fungsi_firewall_for_protecting_important_systems_in_Germany\"><\/span>What is the main fungsi firewall for protecting important systems in Germany?  <i class=\"fa fa-plus\"><\/i><span class=\"ez-toc-section-end\"><\/span><\/h3> \n                        <div class=\"faq_description\">\n                <p>The main job is edge protection, plus dividing networks and deep packet checks. BSI guides for critical areas say keep factory and office networks apart so problems stay small and services like power or trains keep running.\r\n<\/p>\n            <\/div>\n            <\/div>\n                \n                <div class=\"faq\">\n            <h3 class=\"faq_title\"><span class=\"ez-toc-section\" id=\"How_does_the_new_NIS2_rule_through_BSI_law_change_firewall_needs_for_German_companies\"><\/span>How does the new NIS2 rule through BSI law change firewall needs for German companies?  <i class=\"fa fa-plus\"><\/i><span class=\"ez-toc-section-end\"><\/span><\/h3> \n                        <div class=\"faq_description\">\n                <p>It asks about 29,000 groups to use proper technical steps. Leaders are now responsible and must report big problems within 24 hours. Good firewalls with live watching are now required.\r\n<\/p>\n            <\/div>\n            <\/div>\n                \n                <div class=\"faq\">\n            <h3 class=\"faq_title\"><span class=\"ez-toc-section\" id=\"Are_strong_firewalls_easy_to_buy_and_use_for_small_companies_in_Germany\"><\/span>Are strong firewalls easy to buy and use for small companies in Germany?  <i class=\"fa fa-plus\"><\/i><span class=\"ez-toc-section-end\"><\/span><\/h3> \n                        <div class=\"faq_description\">\n                <p>Yes. All-in-one boxes from German makers like Securepoint are not too expensive and can grow. BSI gives free help, and government programs pay part of the cost for better cyber safety against ransomware.\r\n<\/p>\n            <\/div>\n            <\/div>\n                \n                <div class=\"faq\">\n            <h3 class=\"faq_title\"><span class=\"ez-toc-section\" id=\"Which_firewall_types_does_BSI_suggest_and_why\"><\/span>Which firewall types does BSI suggest and why?  <i class=\"fa fa-plus\"><\/i><span class=\"ez-toc-section-end\"><\/span><\/h3> \n                        <div class=\"faq_description\">\n                <p>BSI likes simple packet filters for basic edge control and full application gateways for secret data. For normal use, they say mix firewalls with other tools and choose ones that are easy to update and keep good records.\r\n<\/p>\n            <\/div>\n            <\/div>\n                \n                <div class=\"faq\">\n            <h3 class=\"faq_title\"><span class=\"ez-toc-section\" id=\"How_does_the_fungsi_firewall_help_follow_GDPR_and_BDSG_rules_in_German_groups\"><\/span>How does the fungsi firewall help follow GDPR and BDSG rules in German groups? <i class=\"fa fa-plus\"><\/i><span class=\"ez-toc-section-end\"><\/span><\/h3> \n                        <div class=\"faq_description\">\n                <p>It controls data movement, stops wrong access, and makes clear records. This meets the security steps in Article 32. It also helps find and fix problems fast, so big fines are avoided,d and customers stay trusting.\r\n<\/p>\n            <\/div>\n            <\/div>\n            \n    \n    \n    \n    \n    \n    \n    <\/div>\n\n\u00a0<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Final_Words\"><\/span>Final Words!<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400\">The firewall&#8217;s function is more than a technical part. It is the main shield that lets Germany stay strong in digital work while facing many threats. From BSI watch points to offices in Berlin, knowing what a firewall does helps groups work safely and grow.<\/span><\/p>\n<p><span style=\"font-weight: 400\">As cyber risks get bigger, German groups that choose full firewall plans with local standards and new German tools will not only meet rules but also do very well. Whether you run a big company, small firm, or public office, check and improve your firewall now.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400\">    \t<hr class=\"mt-5\">\n        <div class=\"custom_CTA mt-5\">\n            <div class=\"row\">\n                <div class=\"col-lg-7 align-self-center text-lg-left text-center\">\n                    <h3><span class=\"ez-toc-section\" id=\"Start_Browsing_Privately\"><\/span>Start Browsing Privately!<span class=\"ez-toc-section-end\"><\/span><\/h3>\n                    <p clas=\"mb-0\">iProVPN encrypts your data for protection against hackers and surveillance. Unblock your favorite streaming platforms instantly with the best VPN for streaming.<\/p>\n                <\/div>\n                <div class=\"col-lg-5 align-self-center text-center\">\n                    <a class=\"custom_btn_cta\" href=\"https:\/\/iprovpn.com\/buy-vpn\" title=\"Get iProVPN Now\">Get iProVPN NOW<\/a>\n                <\/div>\n            <\/div>\n    \t<\/div>\n    <\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Germany is a leader in technology and industry across Europe. From busy factories in Bavaria to finance centers in Frankfurt, German companies handle large amounts of important data every day. But more connections mean bigger risks. The German Federal Office for Information Security (BSI) says the IT security situation is tense.\u00a0 Every day, hundreds of [&hellip;]<\/p>\n","protected":false},"author":14,"featured_media":19817,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[522],"tags":[],"class_list":["post-19371","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-guides"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>What Does a Firewall Do?<\/title>\n<meta name=\"description\" content=\"A firewall protects computer networks effectively by filtering incoming and outgoing traffic to block threats and allow safe data flow.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" 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