Search rules (was: Re: A-label definition)

[John C Klensin]

--On Tuesday, 24 June, 2008 12:34 +0200 Patrik Fältström
<patrik at frobbit.se> wrote:

> 
> On 24 jun 2008, at 05.18, Mark Andrews wrote:
> 
>> If you have a host called 0x7f.0x01.example.com and
>> a search list containg example.com the when someone attempts
>> to telnet to 0x7f.0x01 it won't go to the address in the A
>> record associated with 0x7f.0x01.example.com.
> 
> Can not someone write a draft that say "search lists are bad
> for you"?

Written many years ago (I don't have the RFC number handy; Mark
and Frank probably do).


> And then turn off the search list features in software....

While it is usually off by default these days, people keep
discovering (or re-inventing) them.   Note that search lists, or
variations on them that recognize particular labels and
"promote" them, have become extremely popular with IDNs,
especially to simulate IDN TLDs.  We also have searching
implemented on both servers, in resolver-front-end code, and in
various forwarders and DNS query interception systems.  It is
not at all clear to me that introduction of IDN TLDs, when and
if that occurs, will eliminate their use.

While I dislike DNS searching, I fear that getting rid of it is
a lost cause.

    john