-> domain name length
by "Richard J. Sexton"
-> Re: domain name length
by "Richard J. Sexton"
-> RE: domain name length
by Jim Fleming
-> RE: domain name length
by Michael Dillon
-> Re: domain name length
by "Richard J. Sexton"
-> Re: domain name length
by Michael Dillon
-> RE: domain name length
by Jim Fleming
-> Re: NEWDOM: Shared TLD Definition.
by "Rick H. Wesson"
-> Re: NEWDOM: Shared TLD Definition.
by Simon Higgs
----------------------------------------------------------------------
Date: 2 Nov 1996 08:43:03 -0800
From: "Richard J. Sexton"
Subject: domain name length
[second request]
Length of a domain name: according to the relevant
RFC, the SLD and TLD can be 63 characters long.
The Inter.NIC allows only 26 characters
(including "." and the TLD).
Perry pointed out this is *policy* not
and has nothing to to with RFC complience.
Great, so the Inter.NIC is non complient? ;-)
Who sets this "policy"?
If we increase the length of the TLD, which
seems a forgone conclusion (.mall, .tour etc)
do we decrease the size of the SLD?
What should any new "policy" be?
Perhaps I should just ask Chris Ambler
as he and I seem to be the only two
with any semblance of working registry
software.
Chris: what are we doing for domain name
lengths?
- --
Richard J. Sexton
richard@Alter.NIC
----------------------------------------------------------------------
Date: 2 Nov 1996 12:50:08 -0800
From: "Richard J. Sexton"
Subject: Re: domain name length
At 12:00 PM 11/2/96 -0800, you wrote:
>>Perhaps I should just ask Chris Ambler
>>as he and I seem to be the only two
>>with any semblance of working registry
>>software.
>>
>>Chris: what are we doing for domain name
>>lengths?
>
>I am following RFC. I encourage others to do the same.
Do I take this to mean you support 63 character SLD's and
63 character TLD's?
- --
Richard J. Sexton
richard@Alter.NIC
----------------------------------------------------------------------
Date: 2 Nov 1996 12:56:43 -0800
From: Jim Fleming
Subject: RE: domain name length
On Saturday, November 02, 1996 9:45 AM, Richard J.
Sexton[SMTP:richard@Alter.NIC] wrote:
@ At 12:00 PM 11/2/96 -0800, you wrote:
@ >>Perhaps I should just ask Chris Ambler
@ >>as he and I seem to be the only two
@ >>with any semblance of working registry
@ >>software.
@ >>
@ >>Chris: what are we doing for domain name
@ >>lengths?
@ >
@ >I am following RFC. I encourage others to do the same.
@
@ Do I take this to mean you support 63 character SLD's and
@ 63 character TLD's?
@
@ --
@ Richard J. Sexton
@ richard@Alter.NIC
@
@
@
@@@@ http://www.crynwr.com/crynwr/rfc1035/rfc1035.html#3.1.
3.1. Name space definitions
Domain names in messages are expressed in terms of a sequence of labels.
Each label is represented as a one octet length field followed by that number
of octets. Since every domain name ends with the null label of the root, a
domain name is terminated by a length byte of zero. The high order two bits
of every length octet must be zero, and the remaining six bits of the length
field limit the label to 63 octets or less.
To simplify implementations, the total length of a domain name (i.e., label
octets and label length octets) is restricted to 255 octets or less.
Although labels can contain any 8 bit values in octets that make up a label,
it is strongly recommended that labels follow the preferred syntax described
elsewhere in this memo, which is compatible with existing host naming
conventions. Name servers and resolvers must compare labels in a
case-insensitive manner (i.e., A=a), assuming ASCII with zero parity.
Non-alphabetic codes must match exactly.
@@@@
- --
Jim Fleming
UNETY Systems, Inc.
Naperville, IL
e-mail:
JimFleming@unety.net
JimFleming@unety.net.s0.g0 (EDNS/IPv8)
----------------------------------------------------------------------
Date: 2 Nov 1996 13:38:08 -0800
From: Michael Dillon
Subject: RE: domain name length
On Sat, 2 Nov 1996, Jim Fleming wrote:
> @@@@ http://www.crynwr.com/crynwr/rfc1035/rfc1035.html#3.1.
> Domain names in messages are expressed in terms of a sequence of labels.
> Each label is represented as a one octet length field followed by that
number
> of octets. Since every domain name ends with the null label of the root, a
> domain name is terminated by a length byte of zero. The high order two bits
> of every length octet must be zero, and the remaining six bits of the length
> field limit the label to 63 octets or less.
In other words the following is legal according to the RFC
this-is-a-very-very-long-second-level-domain-name-that-is-legal.com
0123456789012345678901234567890123456789012345678901234567890123456
Actually, it is one less than the limit. So the 63 char limit refers to
the portions between the dots.
> To simplify implementations, the total length of a domain name (i.e., label
> octets and label length octets) is restricted to 255 octets or less.
And the 255 character limit applies, I assume, to host names, i.e.
Fully Qualified Domain Names
> Although labels can contain any 8 bit values in octets that make up a label,
> it is strongly recommended that labels follow the preferred syntax described
> elsewhere in this memo, which is compatible with existing host naming
> conventions. Name servers and resolvers must compare labels in a
> case-insensitive manner (i.e., A=a), assuming ASCII with zero parity.
> Non-alphabetic codes must match exactly.
Somewhere this is defined as letters (not case sensitive), numbers and
dash for a total of 37 valid symbols. Some DNS software does check the
validity of this.
So any registry software needs to check against the 255 char limit and
pick apart the name and check each segment against the 63 char limit as a
sanity check. However a domain name of 255 characters is a pathological
case since it cannot have subdomains or host names within it. Also, the
example name above illustrates that the 63 char limit, while useful in
designing code, is not terribly usable in the real world.
So two additional limits need to be imposed by registries to ensure that
the names are likely to be useable in the real world, but perhaps these
can be soft limits with some kind of manual override for the company that
demands to have ben-and-jerrys-ice-cream-treats.inc which is 35 chars
long. I suggest the following:
A. Make sure your databases can store 255 character domain names.
B. Impose a limit of 26 characters on the SLD portion but allow for
manual overrides by registry staff. Charge extra for this service
because you really should explain to the customer that there
is a possibility that this domain name may not work with some software
on the Internet that only knows about the 26 char limit.
Since longer TLD's have more information content I don't see this 26 char
limit as being a problem. If someone registers the .STAR-TREK-FANS
TLD, they still have 11 characters left to create SLD's and the 26
character limit does not apply beyond that so this URL
http://this-is-the-grooviest-website-on-earth.sixties.star-trek-fans
is still perfectly legal. The SLD is less than 26 characters and the
FQDN is less than 255 characters.
Michael Dillon - ISP & Internet Consulting
Memra Software Inc. - Fax: +1-604-546-3049
http://www.memra.com - E-mail: michael@memra.com
----------------------------------------------------------------------
Date: 2 Nov 1996 13:53:33 -0800
From: "Richard J. Sexton"
Subject: Re: domain name length
At 12:58 PM 11/2/96 -0800, you wrote:
>>Do I take this to mean you support 63 character SLD's and
>>63 character TLD's?
1)
>Unless I read the RFC wrong, TLDs can be up to 63 characters, but that's
>for the governing body to decide when handing them out. According to the
>Postel draft, 3, 4, and 5 character TLDs are allowed, so we chose 2 at 3
>characters, and 1 at 4 characters.
2)
>For SLDs, again unless I read the RFC wrong, 63 characters is the maximum.
>Since there is no operational reason not to allow a 63 character SLD, we
>do. If someone can show me why it's a bad idea, I'll listen - but the
>default is always the RFC, no?
If the default was the RFC we'd probably allow 63 character TLD's
That would be, of course, in technical parlance "dopey".
If we adopt a more common sense, ie. practical vs. theoretical
limit, 5 seems ok, although I'd personally use 7, since A)
draft-postel is still a draft, and B) I'm aware of a 7
letter TLD that has a good chance of becoming real.
As long as we're NOT goiung to comply strictly with
the RFC per above, I would suspect 32 characters
is sufficient for a SLD, but I'm far from form on
this, 63 seems to be resonable I suppose.
- --
Richard J. Sexton
richard@Alter.NIC
----------------------------------------------------------------------
Date: 2 Nov 1996 14:00:29 -0800
From: Michael Dillon
Subject: Re: domain name length
On Sat, 2 Nov 1996, Christopher Ambler wrote:
> For SLDs, again unless I read the RFC wrong, 63 characters is the maximum.
I have been using the term SLD to mean the TLD plus . plus the second
level portion and 3LD to mean SLD plus . plus third level portion. I think
most people have been using the term SLD this way. Thus...
.COM is a TLD
PUNK.COM is an SLD
PALO-ALTO.CA.US is a 3LD
> Since there is no operational reason not to allow a 63 character SLD, we
> do. If someone can show me why it's a bad idea, I'll listen - but the
> default is always the RFC, no?
No, the default is not always the RFC. First of all, there is often not
one single RFC that defines things. Often, several different RFC's must be
consulted and somehow reconciled. And sometimes the RFC's are not the only
defining documents. One rule that is used when developping RFC's is to be
conservative in what you send out and liberal in what you accept.
Being conservative in this way ensures that you do not break things with
other people's software implementations even if they may have made
implementation mistakes.
IMHO, the act of registering a domain name is a "sending out" kind of
activity since any domain name that is registered will then be used in
numerous Internet activities, possibly in protocols that none of us have
heard of but which are important to some people on the net. The two
reasons why I favor a 26 character limitation are that it is the
conservative thing to do, and 26 character SLD's allow ample room for
creativity in naming.
However, the liberal rule comes to play when implementing the actual
software at the registry. Make sure it can handle 255 character domains
because some day you may be selling 4LD's and reach that limit. Make sure
you can handle 63 char segments if any of your software breaks apart an
FQDN for any reason.
Michael Dillon - ISP & Internet Consulting
Memra Software Inc. - Fax: +1-604-546-3049
http://www.memra.com - E-mail: michael@memra.com
----------------------------------------------------------------------
Date: 2 Nov 1996 14:07:23 -0800
From: Jim Fleming
Subject: RE: domain name length
On Saturday, November 02, 1996 10:44 AM, Richard J.
Sexton[SMTP:richard@Alter.NIC] wrote:
@ At 12:58 PM 11/2/96 -0800, you wrote:
@ >>Do I take this to mean you support 63 character SLD's and
@ >>63 character TLD's?
@
@ 1)
@
@ >Unless I read the RFC wrong, TLDs can be up to 63 characters, but that's
@ >for the governing body to decide when handing them out. According to the
@ >Postel draft, 3, 4, and 5 character TLDs are allowed, so we chose 2 at 3
@ >characters, and 1 at 4 characters.
@
@ 2)
@
@ >For SLDs, again unless I read the RFC wrong, 63 characters is the maximum.
@ >Since there is no operational reason not to allow a 63 character SLD, we
@ >do. If someone can show me why it's a bad idea, I'll listen - but the
@ >default is always the RFC, no?
@
@ If the default was the RFC we'd probably allow 63 character TLD's
@
@ That would be, of course, in technical parlance "dopey".
@
@ If we adopt a more common sense, ie. practical vs. theoretical
@ limit, 5 seems ok, although I'd personally use 7, since A)
@ draft-postel is still a draft, and B) I'm aware of a 7
@ letter TLD that has a good chance of becoming real.
@
@ As long as we're NOT goiung to comply strictly with
@ the RFC per above, I would suspect 32 characters
@ is sufficient for a SLD, but I'm far from form on
@ this, 63 seems to be resonable I suppose.
@
@ --
@ Richard J. Sexton
@ richard@Alter.NIC
@
@
@
@
From Chris Sevcik's list of useful information...
"The longest word in the English language, according to the Oxford
English Dictionary, is pneumonoultramicroscopicsilicovolcanoconiosis.
The only other word with the same amount of letters is
pneumonoultramicroscopicsilicovolcanoconioses, its plural."
1234567890123456789012345678901234567890
If I counted correctly that is 40...
great...half the size of a keypuch card...and very Biblical
- --
Jim Fleming
UNETY Systems, Inc.
Naperville, IL
e-mail:
JimFleming@unety.net
JimFleming@unety.net.s0.g0 (EDNS/IPv8)
----------------------------------------------------------------------
Date: 2 Nov 1996 19:15:23 -0800
From: "Rick H. Wesson"
Subject: Re: NEWDOM: Shared TLD Definition.
Bill,
How would you defined a shared TLD system. So far this is the only one
I've gotten. I have searched the shared-tld archive and couldnt
find a working definition there either.
- -Rick
On Nov 2, 8:40pm, Bill Broussard wrote:
> Subject: Re: NEWDOM: Shared TLD Definition.
> Perry E. Metzger wrote:
> >
> > "Rick H. Wesson" writes:
> > > > > Could anyone please define a shared TLD for me?
> > > >
> > > > In my mind, it would be a TLD administered by a large group of
> > > > registries rather than by a single registry, possibly using a shared
> > > > lock/database machine to maintain mutual consistancy. A variety of
> > > > legal models are possible.
> > >
> > > Does this model still hold up if the Main database resides
> > > on a local set of machines? It is that a set of distribueted operators
> > > manage the system through the same interfaces. that make sthis a shared
> > > system.
> > >
> > > ie you are not saying 'Shared TLD' = Distributed TLD Databse? but that
> > > its management is distributed.
> >
> > I don't think you can successfully run distributed databases above a
> > certain fairly small size, and besides you are dealing with
> > potentially mutually hostile registries and under those circumstances
> > designing a distribution protocol gets very hard.
> >
> > I would therefore suggest that shared TLD does not mean a distributed
> > database, but rather multiple registries with access to a single
> > database run by a trusted third party, presumably one prohibited by
> > contract from being a registry.
>
> Perry - Why would you make that presumption?
> --
> William Arren Broussard
> Legal, Financial & Business Counseling Services
> P.O. Box 162926
> Austin, Texas 78716-2926
>
>-- End of excerpt from Bill Broussard
- --
Rick H. Wesson
----------------------------------------------------------------------
Date: 2 Nov 1996 22:22:56 -0800
From: Simon Higgs
Subject: Re: NEWDOM: Shared TLD Definition.
At 1:27 PM -0800 11/1/96, Rick H. Wesson wrote:
> Could anyone please define a shared TLD for me?
>
From draft-higgs-tld-cat...
5.1. Openly Competitive TLD Class
Each Openly Competitive TLD must be operated by multiple
registries. Each registry is responsible for registering
secondary domains in a competitive marketplace alongside other
registries.
Simon
- --
"The only thing to prevent what's past is to put a stop to it before it
happens."
-- attributed to Sir Boyle Roche, eighteenth-century member of
Parliament from Tralee, famed for his word-mangling
