Subject: [idn] nameprep in application may break things

From: Dan Oscarsson <[email-masked]>
Date: Wed, 7 Feb 2001 15:02:13 +0100 (MET)

I think having nameprep done in applications will break things.

If you do: nslookup Www.cisco.com
you get as an answer: 
Name:    WWW.cisco.com
Address:  198.133.219.25

If you do: nslookup Www.cisco.com
you get as an answer: 
Name:    Www.cisco.com
Address:  198.133.219.25

If you had nameprep in nslookup the answer in both cases would be:
Name:    www.cisco.com
Address:  198.133.219.25

This will break all scripts calling nslookup and the doing simple
string matching in the answer to test the result.
I am sure there are lots of scripts that expect this behaviour.

   Dan

---

From: Patrik Fältström <[email-masked]>
Date: Wed, 7 Feb 2001 15:35:00 +0100

>I am sure there are lots of scripts that expect this behaviour.

One thing you forget is that applications which handle domainnames 
need to do nameprep, including your "simple script".

Also, I question whether a DNS server rewrite the query part of a DNS 
packet. I doubt any DNS server do that.

Further, I don't understand what you mean by your conclusion. Why 
should nslookup not present the non-nameprepped string to the user? 
You seem to think that nslookup is displaying the string which is the 
output of the nameprep calculation, but it could aswell be the input.

   paf

-- 
Patrik Fältström <[email-masked]>                         Cisco Systems
Consulting Engineer                                  Office of the CSO
Phone: (Stockholm) +46-8-4494212            (San Jose) +1-408-525-0940
        PGP: 2DFC AAF6 16F0 F276 7843  2DC1 BC79 51D9 7D25 B8DC