Re: [dnsext] Some thoughts on the updated aliasing draft

Alex Bligh <> Mon, 28 March 2011 08:50 UTC

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Date: Mon, 28 Mar 2011 09:52:04 +0000
From: Alex Bligh <>
To: Paul Vixie <>,
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Subject: Re: [dnsext] Some thoughts on the updated aliasing draft
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--On 27 March 2011 21:37:06 +0000 Paul Vixie <> wrote:

> these would be, in the parlance used when this topic was first introduced,
> "second class names".  they can't be used as the target of MX or NS RRs,
> and they won't work for services whose servers have not been upgraded.

NS records perhaps, but I'm not sure MX is as big a deal as all that.
Assume the worst happens, and a CNAME is synthesized. This works in
(say) 99% of cases already, and a draft modifying the appropriate
SMTP RFC would legitimise it. I suspect most of the usage for such
names would be IDN related, and that you'd get more breakage from
old SMTP speakers with config files that don't like IDN / new TLDs
than CNAME MXes (I seem to remember my sendmail/uucp config in
93 had all the TLDs hardwired in - it would not be a tragedy if
this ceased to work).

Alex Bligh