Re: [Exim] v6

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Auteur: Kevin Sindhu
Date:  
À: itojun
CC: exim-users, Randy Bush, ph10
Sujet: Re: [Exim] v6
Moin itojun!
itojun@??? schrieb am Thursday, den 18. April 2002:

>>> looks like ph10's guess was correct, the A is being returned
>>> before the AAAA. i suspect my v6 friends would ask that AAAA be
>>> preferred even if it is not first.


>> I presume you mean in the case MX -> name -> two IP addresses, one
>> v4 and one v6 but not in the case MX -> two names, one has A and
>> one has AAAA where of course the MX preferences will determine the
>> order. Is it worth adding an option to Exim specially for this,
>> when your v6 friends can achieve what they want by suitable MX
>> records? I need more convincing...


>     yes, this is the former case.  other IPv6-ready applications (like
>     telnet, ftp, ssh, whatever) uses IPv6 first when a name resolves
>     to multiple addresses with mixed IPv6 ones and IPv4 ones.  the
>     methodology is good for transition (otherwise, we'll keep using
>     IPv4 and transition never happens even if dual stack servers get
>     deployed...).


And I completely agree with you. Even in my case (dig mx
lucifer.at/open-systems.org), I want v6 (AAAA) address to be returned
specifically "before" the v4 so that if the application can do IPv6.

Most apps on NetBSD by default already do this(e.g. ftp/telnet) and I
believe it should be the same for exim.

Kind Regards,

    -Kevin


$ dig mx lucifer.at

    ; <<>> DiG 2.2 <<>> mx lucifer.at
    ;; res options: init recurs defnam dnsrch
    ;; got answer:
    ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 54253
    ;; flags: qr rd ra; Ques: 1, Ans: 3, Auth: 2, Addit: 6
    ;; QUESTIONS:
    ;;      lucifer.at, type = MX, class = IN


    ;; ANSWERS:
    lucifer.at.     6802    MX      0 ipv6.lucifer.at.
    lucifer.at.     6802    MX      10 mail.open-systems.org.
    lucifer.at.     6802    MX      20 mail.greenseek.net.


    ;; AUTHORITY RECORDS:
    lucifer.at.     6802    NS      ns1.zoneedit.com.
    lucifer.at.     6802    NS      ns5.zoneedit.com.


    ;; ADDITIONAL RECORDS:
    ipv6.lucifer.at.        6802    AAAA    3ffe:1200:3028:8d6b::1
    mail.open-systems.org.  19866   AAAA    3ffe:1200:3028:8d6b::1
    mail.open-systems.org.  19866   A       24.84.17.242
    mail.greenseek.net.     19866   A       207.194.231.38
    ns1.zoneedit.com.       151780  A       207.228.252.101
    ns5.zoneedit.com.       137364  A       207.41.71.245


    ;; Total query time: 37 msec
    ;; FROM: satan to SERVER: default -- 24.69.255.195
    ;; WHEN: Thu Apr 18 09:24:57 2002
    ;; MSG SIZE  sent: 28  rcvd: 288



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