In message <BANLkTinAZvLc4oQEW5Nq8eTrch=x6HsbJg@mail.gmail.com>, Jeremy writes:
"DK" may not be hierarchical, but "DK." is. If you try to resolve "DK" on
"DK." is NOT a hostname (RFC 952). It is NOT legal in a SMTP transaction. It is NOT legal in a HTTP header.
it's own, many (most? all?) DNS clients will attach the search string/domain name of the local system in order to make it a FQDN. The same happens when you try and resolve a non-existent domain. Such as alskdiufwfeiuwdr3948dx.com, in wireshark I see the initial request followed by alskdiufwfeiuwdr3948dx.com.gateway.2wire.net. However if I qualify it with the trailing dot, it stops after the first lookup. DK. is a valid FQDN and should be considered hierarchical due to the dot being the root and anything before that is a branch off of the root. see RFC1034
You need to write 1000 lines of: RFC 1034 DOES NOT CHANGE WHAT IS A LEGAL HOSTNAME Go READ RFC 1034. "DK." it is NOT a valid heirachical hostname. Just because some random piece of software lets you get away with it does not make it a legal nor does it make it a good idea. Mark
-Jeremy
On Sun, Jun 19, 2011 at 7:08 PM, Mark Andrews <marka@isc.org> wrote:
In message <g339j59ywz.fsf@nsa.vix.com>, Paul Vixie writes:
Adam Atkinson <ghira@mistral.co.uk> writes:
It was a very long time ago, but I seem to recall being shown http://dk, the home page of Denmark, some time in the mid 90s.
Must I be recalling incorrectly?
no you need not must be. it would work as long as no dk.this or dk.that would be found first in a search list containing 'this' and 'that', where the default search list is normally the parent domain name of your own hostname (so for me on six.vix.com the search list would be vix.com and so as long as dk.vix.com did not exist then http://dk/ would reach "dk.") -- Paul Vixie KI6YSY
DK should NOT be doing this. DK is *not* a hierarchical host name and the address record should not exist, RFC 897. The Internet stopped using simple host names in the early '80s. In addition to that it is a security issue similar to that described in RFC 1535.
Mark -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@isc.org
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"DK" may not be hierarchical, but "DK." is. If you try = to resolve "DK" on it's own, many (most? all?) DNS clients wi= ll attach the search string/domain name of the local system in order to mak= e it a FQDN. The same happens when you try and resolve a non-existent domai= n. Such as <a href=3D"http://alskdiufwfeiuwdr3948dx.com">alskdiufwfeiuwdr39= 48dx.com</a>, in wireshark I see the initial request followed by =A0<meta h= ttp-equiv=3D"content-type" content=3D"text/html; charset=3Dutf-8"><a href= =3D"http://alskdiufwfeiuwdr3948dx.com.gateway.2wire.net">alskdiufwfeiuwdr39= 48dx.com.gateway.2wire.net</a>. However if I qualify it with the trailing d= ot, it stops after the first lookup. DK. is a valid FQDN and should be cons= idered hierarchical due to the dot being the root and anything before that = is a branch off of the root. see RFC1034<div> <br></div><div>-Jeremy<br><br><div class=3D"gmail_quote">On Sun, Jun 19, 20= 11 at 7:08 PM, Mark Andrews <span dir=3D"ltr"><<a href=3D"mailto:marka@i= sc.org">marka@isc.org</a>></span> wrote:<br><blockquote class=3D"gmail_q= uote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1e= x;"> <div><div></div><div class=3D"h5"><br> In message <<a href=3D"mailto:g339j59ywz.fsf@nsa.vix.com">g339j59ywz.fsf= @nsa.vix.com</a>>, Paul Vixie writes:<br> > Adam Atkinson <<a href=3D"mailto:ghira@mistral.co.uk">ghira@mistral= .co.uk</a>> writes:<br> ><br> > > It was a very long time ago, but I seem to recall being shown <a = href=3D"http://dk" target=3D"_blank">http://dk</a>,<br> > > the home page of Denmark, some time in the mid 90s.<br> > ><br> > > Must I be recalling incorrectly?<br> ><br> > no you need not must be. =A0it would work as long as no dk.this or dk.= that<br> > would be found first in a search list containing 'this' and &#= 39;that', where<br> > the default search list is normally the parent domain name of your own= <br> > hostname (so for me on <a href=3D"http://six.vix.com" target=3D"_blank= ">six.vix.com</a> the search list would be <a href=3D"http://vix.com" targe= t=3D"_blank">vix.com</a> and<br> > so as long as <a href=3D"http://dk.vix.com" target=3D"_blank">dk.vix.c= om</a> did not exist then <a href=3D"http://dk/" target=3D"_blank">http://d= k/</a> would reach "dk.")<br> > --<br> > Paul Vixie<br> > KI6YSY<br> <br> </div></div>DK should NOT be doing this. =A0DK is *not* a hierarchical host= name<br> and the address record should not exist, RFC 897. =A0The Internet<br> stopped using simple host names in the early '80s. =A0In addition to<br=
that it is a security issue similar to that described in RFC 1535.<br> <br> Mark<br> <font color=3D"#888888">--<br> Mark Andrews, ISC<br> 1 Seymour St., Dundas Valley, NSW 2117, Australia<br> PHONE: <a href=3D"tel:%2B61%202%209871%204742" value=3D"+61298714742">+61 2= 9871 4742</a> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 INTERNET: <a href=3D"mailto:= marka@isc.org">marka@isc.org</a><br> <br> </font></blockquote></div><br></div>
--bcaec51f900961620b04a619d97b-- -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@isc.org