Re: Multiple Mail domains for reverse ptr records? I'm confused

From: Wietse Venema (no email)
Date: Fri Nov 27 2009 - 13:09:34 EST

  • Next message: Wietse Venema: "Re: Multiple Mail domains for reverse ptr records? I'm confused"

    Greg A. Woods:
    > There _should_ be one PTR for every _valid_ hostname using a given IP
    > address.

    Statements such as above remind me of silly knights fighting windmills.

    There is a difference between "right" and "useful", and it even
    depends on where they are used - server or client side.

    Multiple server A records are useful. More in the case of HTTP,
    less in the case of SMTP which uses indirection via MX records.
    (For a discussion about domain-in-a-box applications, see some
    actual measurements that I did earlier this year).

    One PTR per A record is not useful. The server end will not know
    what client name to use.

    On the other hand, it is right when every PTR record has a matching
    A record that resolves to (among others) the PTR record's address.

            Wietse


  • Next message: Wietse Venema: "Re: Multiple Mail domains for reverse ptr records? I'm confused"





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