[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$f2em5cnxmtd0x2":3},{"type":4,"solution":5},"solution",{"slug":6,"platform":7,"title":8,"description":9,"risk":10,"categorySlug":11,"tags":12,"verifiedAt":22,"updatedAt":22,"categoryName":23,"command":24,"undoCommand":25,"directAnswer":26,"explanation":27,"warning":25,"seoTitle":28,"seoDescription":29,"requirements":25,"macosSupport":30,"sources":31,"related":38},"test-port-connectivity","macos","Test if a host and port are reachable on Mac","Check TCP connectivity to any server, useful for firewall debugging.","low","network",[13,16,19],{"slug":14,"name":15},"diagnostics","Diagnostics",{"slug":17,"name":18},"dns","DNS",{"slug":20,"name":21},"terminal","Terminal","2025-11-13T00:00:00.000Z","Network","nc -vz example.com 443",null,"Replace example.com and 443 with your host and port, then run the command. 'succeeded!' means the TCP port is open and reachable.","nc (netcat) opens a raw TCP connection to the host and port, then closes it. -v prints the result and -z means 'scan only, send no data'. If it hangs or fails, the port is blocked — either by the remote server or by a firewall\u002Fproxy between you and it.","Test Port Connectivity on Mac — nc Command","Check whether a host and TCP port are reachable from macOS using the built-in nc command.","macOS 10.11 El Capitan – 15 Sequoia",[32],{"url":33,"title":34,"publisher":35,"sourceType":36,"evidence":37,"retrievedAt":22},"https:\u002F\u002Fss64.com\u002Fmac\u002Fnc.html","nc — netcat, arbitrary TCP and UDP connections","SS64","technical","nc -vz tests whether a TCP connection can be established and reports success\u002Ffailure.",[39,49,62],{"slug":40,"platform":7,"title":41,"description":42,"risk":43,"categorySlug":11,"tags":44,"verifiedAt":48,"updatedAt":48},"flush-dns-cache","Flush the DNS cache on Mac","Clear cached DNS lookups when a site resolves to a stale IP address.","medium",[45,46,47],{"slug":17,"name":18},{"slug":14,"name":15},{"slug":20,"name":21},"2025-11-18T00:00:00.000Z",{"slug":50,"platform":7,"title":51,"description":52,"risk":10,"categorySlug":53,"tags":54,"verifiedAt":61,"updatedAt":61},"find-process-using-port","Find which process is using a port on Mac","Identify the app holding port 8080 (or any other port).","developer",[55,57,60],{"slug":56,"name":56},"lsof",{"slug":58,"name":59},"processes","Processes",{"slug":14,"name":15},"2025-11-16T00:00:00.000Z",{"slug":63,"platform":7,"title":64,"description":65,"risk":43,"categorySlug":66,"tags":67,"verifiedAt":75,"updatedAt":75},"show-wifi-password","Show a saved Wi-Fi password on Mac","Reveal the password of a network your Mac has joined before.","security",[68,71,74],{"slug":69,"name":70},"keychain","Keychain",{"slug":72,"name":73},"wifi","Wi-Fi",{"slug":14,"name":15},"2025-11-17T00:00:00.000Z"]