[{"data":1,"prerenderedAt":41},["ShallowReactive",2],{"$fl233b7rspzkt":3},{"title":4,"seoTitle":5,"description":6,"route":7,"kind":8,"toolKey":9,"intro":10,"indexable":11,"sections":12,"related":38},"CNAME 查询","CNAME 查询 | nslookup.online","查询 CNAME 别名及目标链，识别循环和查询未完成状态，补充检查终点 A\u002FAAAA，不将无地址简单判为无效。","\u002Fzh\u002Fcname-lookup\u002F","tool","cname","跟随域名别名链，查看目标与终点地址。",true,[13,20,26,32],{"id":14,"title":15,"paragraphs":16,"code":19},"read-answer","从准确的别名名称开始",[17,18],"CNAME 将一个 DNS 名称指向另一个名称。请查询实际别名，例如 www.example.com，而不是假定所有子域都与根域相同。","CNAME 是 DNS 层的别名，不会改变浏览器地址栏或网页路径。网站跳转需要另外配置 HTTP 重定向。","www.example.com.  300 IN CNAME edge.example.net.\nedge.example.net. 300 IN A     192.0.2.10\n\n文档示例 — 非实时 DNS 响应",{"id":21,"title":22,"paragraphs":23},"endpoint","跟随别名并检查终点",[24,25],"工具逐步跟随 CNAME，记录访问过的名称并识别循环。终点补充查询 A 与 AAAA，使用的仍是所选递归解析器。","最多跟随十跳是产品安全限制，并非 DNS 协议上限。超时、循环或达到上限时会保留证据并标记未完成。",{"id":27,"title":28,"paragraphs":29},"errors","不要把无地址等同于别名错误",[30,31],"终点没有 A\u002FAAAA，不能单独证明别名无效；应结合所需服务、其他记录及提供商说明。NXDOMAIN 则是解析器对名称不存在的明确响应。","普通 CNAME 通常不能与同名的其他数据共存。根域需有 SOA、NS，因此不要把服务商 ALIAS、ANAME 或 flattening 标签直接等同于公开 CNAME。",{"id":33,"title":34,"paragraphs":35},"questions","排查链路差异",[36,37],"比较前先匹配名称、类型和解析器。别名与地址记录可有不同 TTL，其缓存不一定同步更新。","工具不直接连接每个权威服务器，也不证明网站 TLS、HTTP 或应用服务已正常；请保留原配置并在提供商处核验。",[39,40],"\u002Fguides\u002Fa-record-vs-cname\u002F","\u002F",1792661399244]