{"id":17151,"date":"2026-03-22T08:30:15","date_gmt":"2026-03-22T05:30:15","guid":{"rendered":"https:\/\/blog.sh.com.tr\/?p=17151"},"modified":"2026-01-28T13:22:17","modified_gmt":"2026-01-28T10:22:17","slug":"bir-ag-guvenlik-duvari-nedir-ve-nasil-calisir","status":"publish","type":"post","link":"https:\/\/sh.com.tr\/blog\/bir-ag-guvenlik-duvari-nedir-ve-nasil-calisir\/","title":{"rendered":"Bir A\u011f G\u00fcvenlik Duvar\u0131 Nedir ve Nas\u0131l \u00c7al\u0131\u015f\u0131r?"},"content":{"rendered":"

Dijital \u00e7a\u011fda kurumlar\u0131n ve bireylerin en b\u00fcy\u00fck \u00f6nceliklerinden biri, siber g\u00fcvenlik<\/strong>tir. \u0130nternete ba\u011fl\u0131 her sistem, potansiyel sald\u0131r\u0131lara veya yetkisiz eri\u015fimlere a\u00e7\u0131kt\u0131r. Bu tehditlere kar\u015f\u0131 en temel savunma ara\u00e7lar\u0131ndan biri ise a\u011f g\u00fcvenlik duvar\u0131 (firewall)<\/strong> olarak kar\u015f\u0131m\u0131za \u00e7\u0131kar.<\/p>\n

Bu yaz\u0131da, a\u011f g\u00fcvenlik duvar\u0131n\u0131n ne oldu\u011funu, nas\u0131l \u00e7al\u0131\u015ft\u0131\u011f\u0131n\u0131 ve siber g\u00fcvenlikteki rol\u00fcn\u00fc<\/strong> detayl\u0131 \u015fekilde inceleyece\u011fiz.<\/p>\n

A\u011f G\u00fcvenlik Duvar\u0131 Nedir?<\/strong><\/h3>\n

A\u011f g\u00fcvenlik duvar\u0131<\/strong>, i\u00e7 a\u011f ile d\u0131\u015f d\u00fcnya aras\u0131ndaki veri trafi\u011fini kontrol eden bir g\u00fcvenlik sistemidir. Temel amac\u0131, izin verilen trafi\u011fi kabul etmek, \u015f\u00fcpheli veya yetkisiz trafi\u011fi engellemektir<\/strong>.<\/p>\n

Basit bir ifadeyle g\u00fcvenlik duvar\u0131, bir \u015firketin veya bireyin bilgisayar a\u011f\u0131 i\u00e7in giri\u015f kap\u0131s\u0131nda duran g\u00fcvenlik g\u00f6revlisi<\/strong> gibidir. Gelen ve giden her veri paketini kontrol eder, belirlenen kurallara uymayanlar\u0131 durdurur.<\/p>\n

G\u00fcvenlik Duvar\u0131n\u0131n Temel G\u00f6revleri<\/strong><\/h3>\n
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    Eri\u015fim kontrol\u00fc:<\/strong> Kimlerin veya hangi IP adreslerinin a\u011fa girebilece\u011fini belirler.<\/p>\n<\/li>\n

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    Tehdit \u00f6nleme:<\/strong> K\u00f6t\u00fc ama\u00e7l\u0131 yaz\u0131l\u0131mlar\u0131, siber sald\u0131r\u0131lar\u0131 veya \u015f\u00fcpheli ba\u011flant\u0131lar\u0131 engeller.<\/p>\n<\/li>\n

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    Trafik izleme:<\/strong> A\u011fdan ge\u00e7en verilerin kay\u0131tlar\u0131n\u0131 tutar.<\/p>\n<\/li>\n

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    Politika uygulama:<\/strong> \u015eirket g\u00fcvenlik politikalar\u0131na g\u00f6re filtreleme yapar.<\/p>\n<\/li>\n<\/ul>\n

    G\u00fcvenlik Duvar\u0131 T\u00fcrleri<\/strong><\/h3>\n

    \u21d2Paket Filtreleme (Packet Filtering)<\/strong><\/h4>\n

    En temel g\u00fcvenlik duvar\u0131 t\u00fcr\u00fcd\u00fcr. Veri paketlerini kayna\u011f\u0131, hedefi, protokol ve port bilgisine g\u00f6re denetler.<\/p>\n

    \u21d2Durum Denetimli G\u00fcvenlik Duvar\u0131 (Stateful Firewall)<\/strong><\/h4>\n

    Veri paketlerini yaln\u0131zca ba\u015fl\u0131k bilgisine g\u00f6re de\u011fil, ayn\u0131 zamanda ba\u011flant\u0131 durumuna g\u00f6re analiz eder. Daha geli\u015fmi\u015f koruma sa\u011flar.<\/p>\n

    \u21d2Uygulama Katman\u0131 G\u00fcvenlik Duvar\u0131 (Application Firewall)<\/strong><\/h4>\n

    Belirli uygulamalara (\u00f6rne\u011fin web taray\u0131c\u0131, e-posta istemcisi) y\u00f6nelik trafi\u011fi denetler. SQL injection veya XSS gibi sald\u0131r\u0131lara kar\u015f\u0131 koruma sunar.<\/p>\n

    \u21d2Yeni Nesil G\u00fcvenlik Duvar\u0131 (Next-Generation Firewall \u2013 NGFW)<\/strong><\/h4>\n

    IPS (Intrusion Prevention System), derin paket analizi ve tehdit istihbarat\u0131 entegrasyonu ile geli\u015fmi\u015f g\u00fcvenlik sa\u011flar.<\/p>\n

    A\u011f G\u00fcvenlik Duvar\u0131 Nas\u0131l \u00c7al\u0131\u015f\u0131r?<\/strong><\/h3>\n

    G\u00fcvenlik duvar\u0131, \u00f6nceden tan\u0131mlanm\u0131\u015f kurallar<\/strong> ve ger\u00e7ek zamanl\u0131 analiz<\/strong> kullanarak \u00e7al\u0131\u015f\u0131r.<\/p>\n

    \u2022Veri Paketi \u0130ncelemesi<\/strong><\/p>\n

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        Kaynak ve hedef IP adresi kontrol edilir.<\/p>\n<\/li>\n

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        Port ve protokol bilgisi incelenir.<\/p>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

        \u2022Kurallar ile Kar\u015f\u0131la\u015ft\u0131rma<\/strong><\/p>\n

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            Belirlenen g\u00fcvenlik politikalar\u0131na uygun ise trafik kabul edilir.<\/p>\n<\/li>\n

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            \u015e\u00fcpheli ya da yasakl\u0131 trafik engellenir.<\/p>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

            \u2022Kay\u0131t ve \u0130zleme<\/strong><\/p>\n

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                Her trafik hareketi log dosyalar\u0131na kaydedilir.<\/p>\n<\/li>\n

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                G\u00fcvenlik ekipleri anormallikleri takip eder.<\/p>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

                G\u00fcvenlik Duvar\u0131 Kullan\u0131m\u0131n\u0131n Avantajlar\u0131<\/strong><\/h3>\n
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                  Yetkisiz eri\u015fimi engeller.<\/strong><\/p>\n<\/li>\n

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                  A\u011f trafi\u011fini d\u00fczenler.<\/strong><\/p>\n<\/li>\n

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                  Sald\u0131r\u0131lara kar\u015f\u0131 ilk savunma hatt\u0131n\u0131 olu\u015fturur.<\/strong><\/p>\n<\/li>\n

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                  Politikalarla uyumlu bir g\u00fcvenlik ortam\u0131 sa\u011flar.<\/strong><\/p>\n<\/li>\n<\/ul>\n

                  Ancak unutulmamal\u0131d\u0131r ki, g\u00fcvenlik duvar\u0131 tek ba\u015f\u0131na yeterli de\u011fildir. Antivir\u00fcs, IDS\/IPS sistemleri, g\u00fcvenlik yamalar\u0131 ve kullan\u0131c\u0131 fark\u0131ndal\u0131\u011f\u0131 ile birlikte kullan\u0131lmal\u0131d\u0131r.<\/p>\n

                  \u00d6rnek Senaryolar<\/strong><\/h3>\n
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                    \u015eirket a\u011flar\u0131nda:<\/strong> \u00c7al\u0131\u015fanlar\u0131n yaln\u0131zca belirli IP adreslerinden eri\u015fmesine izin verilir.<\/p>\n<\/li>\n

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                    Ki\u015fisel bilgisayarlarda:<\/strong> G\u00fcvenlik duvar\u0131, bilinmeyen uygulamalar\u0131n internet ba\u011flant\u0131s\u0131n\u0131 engeller.<\/p>\n<\/li>\n

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                    E-ticaret sitelerinde:<\/strong> Yetkisiz giri\u015fimlere kar\u015f\u0131 web uygulamas\u0131 g\u00fcvenlik duvar\u0131 (WAF) kullan\u0131l\u0131r.<\/p>\n<\/li>\n<\/ul>\n

                    Bir a\u011f g\u00fcvenlik duvar\u0131<\/strong>, siber g\u00fcvenlikte ilk savunma hatt\u0131d\u0131r. Do\u011fru yap\u0131land\u0131r\u0131ld\u0131\u011f\u0131nda hem bireysel kullan\u0131c\u0131lar hem de kurumlar i\u00e7in kritik koruma sa\u011flar. Ancak etkili bir g\u00fcvenlik stratejisi i\u00e7in g\u00fcvenlik duvar\u0131, di\u011fer siber g\u00fcvenlik \u00f6nlemleriyle birlikte uygulanmal\u0131d\u0131r.<\/p>\n","protected":false},"excerpt":{"rendered":"

                    Dijital \u00e7a\u011fda kurumlar\u0131n ve bireylerin en b\u00fcy\u00fck \u00f6nceliklerinden biri, siber g\u00fcvenliktir. \u0130nternete ba\u011fl\u0131 her sistem, potansiyel sald\u0131r\u0131lara veya yetkisiz eri\u015fimlere a\u00e7\u0131kt\u0131r. Bu tehditlere kar\u015f\u0131 en temel savunma ara\u00e7lar\u0131ndan biri ise a\u011f g\u00fcvenlik duvar\u0131 (firewall) olarak kar\u015f\u0131m\u0131za \u00e7\u0131kar. Bu yaz\u0131da, a\u011f g\u00fcvenlik duvar\u0131n\u0131n ne oldu\u011funu, nas\u0131l \u00e7al\u0131\u015ft\u0131\u011f\u0131n\u0131 ve siber g\u00fcvenlikteki rol\u00fcn\u00fc detayl\u0131 \u015fekilde inceleyece\u011fiz. A\u011f G\u00fcvenlik […]<\/p>\n","protected":false},"author":7,"featured_media":17152,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[238],"tags":[2027,2029,2028],"class_list":["post-17151","post","type-post","status-publish","format-standard","has-post-thumbnail","category-network","tag-ag-guvenlik-duvari-nedir","tag-guvenlik-duvari-ornekleri","tag-guvenlik-duvari-turleri"],"_links":{"self":[{"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/posts\/17151","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/comments?post=17151"}],"version-history":[{"count":1,"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/posts\/17151\/revisions"}],"predecessor-version":[{"id":17537,"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/posts\/17151\/revisions\/17537"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/media\/17152"}],"wp:attachment":[{"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/media?parent=17151"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/categories?post=17151"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sh.com.tr\/blog\/wp-json\/wp\/v2\/tags?post=17151"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}