[{"data":1,"prerenderedAt":41},["ShallowReactive",2],{"$f68uyytz06f75":3},{"title":4,"seoTitle":5,"description":6,"route":7,"kind":8,"toolKey":9,"intro":10,"indexable":11,"sections":12,"related":38},"反向 DNS 查詢","反向 DNS 查詢 | nslookup.online","支援 IPv4、IPv6 的反向 DNS 與 PTR 查詢，顯示完整反向名稱及全部回應，不枚舉同 IP 網站。","\u002Fzh-tw\u002Freverse-dns-lookup\u002F","tool","reverse","輸入 IPv4 或 IPv6，讀取 PTR 主機名稱。",true,[13,20,26,32],{"id":14,"title":15,"paragraphs":16,"code":19},"read-answer","由 IP 查詢名稱",[17,18],"PTR 從 IP 查名稱。IPv4 將四段數字倒序接至 in-addr.arpa；IPv6 展開十六進位位元後倒序放至 ip6.arpa。","本頁接收 IP，首頁選 PTR 也可輸入完整反向名稱。不支援含區域識別碼的 IPv6。","192.0.2.10 → 10.2.0.192.in-addr.arpa\n2001:db8::1 → ip6.arpa 下的倒序十六進位名稱\n\n文件範例 — 非即時 DNS 回應",{"id":21,"title":22,"paragraphs":23},"meaning","PTR 不列出全部網站",[24,25],"PTR 是位址管理方發布的名稱，不是該 IP 託管網站的清單。同一伺服器可有很多網站，也可無 PTR。","反向 DNS 不是 Reverse IP 搜尋，不掃描連接埠，也不能判斷 IP 安全信譽。",{"id":27,"title":28,"paragraphs":29},"limits","正向與反向分開管理",[30,31],"A\u002FAAAA 與 PTR 可能由不同機構管理，修改其中一方不會自動更新另一方。PTR 變更通常需洽 IP 或託管提供商。","無 PTR 不代表離線、不可連線或不安全。郵件對反向 DNS 的要求應另查實際策略。",{"id":33,"title":34,"paragraphs":35},"questions","解讀結果與故障",[36,37],"顯示全部 PTR、TTL、解析器與時間。NOERROR 無 PTR 不同於 NXDOMAIN，逾時也不能當作不存在。","比較前匹配完整反向名稱與解析器，並留意快取。回傳名稱不能證明正向位址與應用正確。",[39,40],"\u002F","\u002Fguides\u002Fnslookup-command\u002F",1792661399393]