[{"data":1,"prerenderedAt":229},["ShallowReactive",2],{"term-f\u002Ffirewall":3,"related-f\u002Ffirewall":211},{"id":4,"title":5,"acronym":6,"body":7,"category":192,"description":193,"difficulty":194,"extension":195,"letter":196,"meta":197,"navigation":120,"path":198,"related":199,"seo":205,"sitemap":206,"stem":209,"subcategory":6,"__hash__":210},"terms\u002Fterms\u002Ff\u002Ffirewall.md","Firewall",null,{"type":8,"value":9,"toc":186},"minimark",[10,15,19,23,26,30,175,179,182],[11,12,14],"h2",{"id":13},"eli5-the-vibe-check","ELI5 — The Vibe Check",[16,17,18],"p",{},"A firewall is the bouncer at your network's door. It checks every incoming and outgoing connection against a list of rules and blocks anything suspicious. Only allow traffic on port 80 and 443? The firewall enforces that. Block traffic from certain countries? Firewall handles it.",[11,20,22],{"id":21},"real-talk","Real Talk",[16,24,25],{},"A firewall is a network security system that monitors and controls incoming and outgoing traffic based on predetermined security rules. Types include packet filtering, stateful inspection, application-layer (layer 7), and next-gen firewalls. Can be hardware, software, or cloud-based.",[11,27,29],{"id":28},"show-me-the-code","Show Me The Code",[31,32,37],"pre",{"className":33,"code":34,"language":35,"meta":36,"style":36},"language-bash shiki shiki-themes material-theme-lighter material-theme material-theme-palenight","# UFW (Ubuntu Firewall) commands\nufw enable\nufw allow 22      # Allow SSH\nufw allow 80      # Allow HTTP\nufw allow 443     # Allow HTTPS\nufw deny 3306     # Block MySQL from outside\n\n# Allow specific IP\nufw allow from 192.168.1.100 to any port 22\n\n# View rules\nufw status verbose\n","bash","",[38,39,40,49,60,75,88,101,115,122,128,153,158,164],"code",{"__ignoreMap":36},[41,42,45],"span",{"class":43,"line":44},"line",1,[41,46,48],{"class":47},"sHwdD","# UFW (Ubuntu Firewall) commands\n",[41,50,52,56],{"class":43,"line":51},2,[41,53,55],{"class":54},"sBMFI","ufw",[41,57,59],{"class":58},"sfazB"," enable\n",[41,61,63,65,68,72],{"class":43,"line":62},3,[41,64,55],{"class":54},[41,66,67],{"class":58}," allow",[41,69,71],{"class":70},"sbssI"," 22",[41,73,74],{"class":47},"      # Allow SSH\n",[41,76,78,80,82,85],{"class":43,"line":77},4,[41,79,55],{"class":54},[41,81,67],{"class":58},[41,83,84],{"class":70}," 80",[41,86,87],{"class":47},"      # Allow HTTP\n",[41,89,91,93,95,98],{"class":43,"line":90},5,[41,92,55],{"class":54},[41,94,67],{"class":58},[41,96,97],{"class":70}," 443",[41,99,100],{"class":47},"     # Allow HTTPS\n",[41,102,104,106,109,112],{"class":43,"line":103},6,[41,105,55],{"class":54},[41,107,108],{"class":58}," deny",[41,110,111],{"class":70}," 3306",[41,113,114],{"class":47},"     # Block MySQL from outside\n",[41,116,118],{"class":43,"line":117},7,[41,119,121],{"emptyLinePlaceholder":120},true,"\n",[41,123,125],{"class":43,"line":124},8,[41,126,127],{"class":47},"# Allow specific IP\n",[41,129,131,133,135,138,141,144,147,150],{"class":43,"line":130},9,[41,132,55],{"class":54},[41,134,67],{"class":58},[41,136,137],{"class":58}," from",[41,139,140],{"class":70}," 192.168.1.100",[41,142,143],{"class":58}," to",[41,145,146],{"class":58}," any",[41,148,149],{"class":58}," port",[41,151,152],{"class":70}," 22\n",[41,154,156],{"class":43,"line":155},10,[41,157,121],{"emptyLinePlaceholder":120},[41,159,161],{"class":43,"line":160},11,[41,162,163],{"class":47},"# View rules\n",[41,165,167,169,172],{"class":43,"line":166},12,[41,168,55],{"class":54},[41,170,171],{"class":58}," status",[41,173,174],{"class":58}," verbose\n",[11,176,178],{"id":177},"when-youll-hear-this","When You'll Hear This",[16,180,181],{},"\"The firewall is blocking port 5432 — open it for the database server.\" \u002F \"Configure the firewall to only allow SSH from trusted IPs.\"",[183,184,185],"style",{},"html pre.shiki code .sHwdD, html code.shiki .sHwdD{--shiki-light:#90A4AE;--shiki-light-font-style:italic;--shiki-default:#546E7A;--shiki-default-font-style:italic;--shiki-dark:#676E95;--shiki-dark-font-style:italic}html pre.shiki code .sBMFI, html code.shiki .sBMFI{--shiki-light:#E2931D;--shiki-default:#FFCB6B;--shiki-dark:#FFCB6B}html pre.shiki code .sfazB, html code.shiki .sfazB{--shiki-light:#91B859;--shiki-default:#C3E88D;--shiki-dark:#C3E88D}html pre.shiki code .sbssI, html code.shiki .sbssI{--shiki-light:#F76D47;--shiki-default:#F78C6C;--shiki-dark:#F78C6C}html .light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html.light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html .default .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}html.dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}",{"title":36,"searchDepth":51,"depth":51,"links":187},[188,189,190,191],{"id":13,"depth":51,"text":14},{"id":21,"depth":51,"text":22},{"id":28,"depth":51,"text":29},{"id":177,"depth":51,"text":178},"networking","A firewall is the bouncer at your network's door. It checks every incoming and outgoing connection against a list of rules and blocks anything suspicious.","beginner","md","f",{},"\u002Fterms\u002Ff\u002Ffirewall",[200,201,202,203,204],"Port","NAT","VPN","Security","CIDR",{"title":5,"description":193},{"changefreq":207,"priority":208},"weekly",0.7,"terms\u002Ff\u002Ffirewall","4twjMAQdIBXYbu1gB-DxOAA9jT9-vHha6ZOsQ5Y_FQM",[212,217,221,225],{"title":204,"path":213,"acronym":214,"category":192,"difficulty":215,"description":216},"\u002Fterms\u002Fc\u002Fcidr","Classless Inter-Domain Routing","intermediate","CIDR is the shorthand notation for specifying IP address ranges. '192.168.1.",{"title":201,"path":218,"acronym":219,"category":192,"difficulty":215,"description":220},"\u002Fterms\u002Fn\u002Fnat","Network Address Translation","NAT is how your home router lets all your devices share one public IP address. Your phone, laptop, and TV each get a private IP (192.168.x.",{"title":200,"path":222,"acronym":6,"category":223,"difficulty":194,"description":224},"\u002Fterms\u002Fp\u002Fport","general","A port is like an apartment number on a building. Your computer is the building (localhost), and multiple services live inside.",{"title":202,"path":226,"acronym":227,"category":192,"difficulty":194,"description":228},"\u002Fterms\u002Fv\u002Fvpn","Virtual Private Network","A VPN creates an encrypted tunnel from your device to a server somewhere else.",1776518280189]