CNAME to CNAME

不知道是從哪邊傳出 CNAME 不能設到 CNAME 的觀念,剛剛特地找資料,發現可能被「誤解」的地方。

RFC 1034 裡因為效率問題「建議」不要 CNAME to CNAME,但也強調這不應該視為錯誤:(5.2.2. Aliases)

Multiple levels of aliases should be avoided due to their lack of efficiency, but should not be signalled as an error.

參考:「Cname of Cname」。

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2 Responses to CNAME to CNAME

  1. timdream says:

    我一直在想,如果手賤把 CNAME chain 故意設很長,有沒有可能把現有的瀏覽器/OS 的 implantation 搞壞 (例如發現某 M 廠商的 nslookup 只會 follow 幾次之類的).... 不想惡搞 everydns 所以就沒有玩了~

  2. 現在的 resolver 都有 loop detection,所以不要 CNAME 到爆應該都沒問題...

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