After .nyc thread, thought this IAB announcement may be of interest.
-Jon
Here's a list of TLD's who currently have A records on the TLD as mentioned
by IAB
AC 193.223.78.210
AI 209.59.119.34
BO 166.114.1.28
CM 195.24.205.60
DK 193.163.102.24
GG 87.117.196.80
IO 193.223.78.212
JE 87.117.196.80
KH 203.223.32.21
PN 80.68.93.100
SH 193.223.78.211
TK 217.119.57.22
TM 193.223.78.213
TO 216.74.32.107
UZ 91.212.89.8
VI 193.0.0.198
WS 64.70.19.33
Tony
Whilst I am not a fan of dotless domains, as long as one uses the fully
qualified domain name (e.g. http://ac./), there should not be any
trouble using it in any sane software. It seems that most people aren't
aware these days that a fqdn includes the trailing period (by definition).
If the definition of "FQDN" in some RFCs (Informational or not) always
included the trailing dot, I'd be inclined to agree with you. But that's
not the case, so protocol slots have been established for "FQDNs" that are
actually domains qualified relative to the root. Since this ambiguity has
been around since the very dawn of the DNS, I suspect there is little
chance of re-educating everyone in the world about this.
A
Most of us would have no problem doing it, but the majority of users don't
even understand why there's dots in the first place let any why they'd need
to put one for nyc but not for facebook.com
-gp
No it does not. Period at the end is a local convention to stop
searching on some platforms. It is not syntactically legal. Note
the words 'a sequence of domain labels separated by "."'. Periods
at the end are NOT legal.
RFC 1738
host
The fully qualified domain name of a network host, or its IP
address as a set of four decimal digit groups separated by
".". Fully qualified domain names take the form as described
in Section 3.5 of RFC 1034 [13] and Section 2.1 of RFC 1123
[5]: a sequence of domain labels separated by ".", each domain
label starting and ending with an alphanumerical character and
possibly also containing "-" characters. The rightmost domain
label will never start with a digit, though, which
syntactically distinguishes all domain names from the IP
addresses.
Mark
Mark Andrews <marka@isc.org> writes:
> Whilst I am not a fan of dotless domains, as long as one uses the fully
> qualified domain name (e.g. http://ac./), there should not be any
> trouble using it in any sane software. It seems that most people aren't
> aware these days that a fqdn includes the trailing period (by definition).No it does not. Period at the end is a local convention to stop
searching on some platforms. It is not syntactically legal. Note
the words 'a sequence of domain labels separated by "."'. Periods
at the end are NOT legal.RFC 1738
host
The fully qualified domain name of a network host, or its IP
address as a set of four decimal digit groups separated by
".". Fully qualified domain names take the form as described
in Section 3.5 of RFC 1034 [13] and Section 2.1 of RFC 1123
[5]: a sequence of domain labels separated by ".", each domain
label starting and ending with an alphanumerical character and
possibly also containing "-" characters. The rightmost domain
label will never start with a digit, though, which
syntactically distinguishes all domain names from the IP
addresses.
That was fixed in RFC 2396:
host = hostname | IPv4address
hostname = *( domainlabel "." ) toplabel [ "." ]
... The rightmost
domain label of a fully qualified domain name will never start with a
digit, thus syntactically distinguishing domain names from IPv4
addresses, and may be followed by a single "." if it is necessary to
distinguish between the complete domain name and any local domain.
However, I think it's safe to say this is an edge case and chances are
you'll have trouble using dotless domains with some software and
processes. For example, you'll probably have trouble getting a SSL
certificate.
Mark Andrews <marka@isc.org> writes:
Whilst I am not a fan of dotless domains, as long as one uses the fully
qualified domain name (e.g. http://ac./), there should not be any
trouble using it in any sane software. It seems that most people aren't
aware these days that a fqdn includes the trailing period (by definition).No it does not. Period at the end is a local convention to stop
searching on some platforms. It is not syntactically legal. Note
the words 'a sequence of domain labels separated by "."'. Periods
at the end are NOT legal.RFC 1738
host
The fully qualified domain name of a network host, or its IP
address as a set of four decimal digit groups separated by
".". Fully qualified domain names take the form as described
in Section 3.5 of RFC 1034 [13] and Section 2.1 of RFC 1123
[5]: a sequence of domain labels separated by ".", each domain
label starting and ending with an alphanumerical character and
possibly also containing "-" characters. The rightmost domain
label will never start with a digit, though, which
syntactically distinguishes all domain names from the IP
addresses.That was fixed in RFC 2396:
... which has the title, "Uniform Resource Identifiers (URI): Generic Syntax," so not necessarily a treatise on host name syntax. 
host = hostname | IPv4address
hostname = *( domainlabel "." ) toplabel [ "." ]... The rightmost
domain label of a fully qualified domain name will never start with a
digit, thus syntactically distinguishing domain names from IPv4
addresses, and may be followed by a single "." if it is necessary to
distinguish between the complete domain name and any local domain.However, I think it's safe to say this is an edge case and chances are
you'll have trouble using dotless domains with some software and
processes.
Right-o. And even if 2396 was authoritative, the "may" in "may be followed" highlights the point Mark made earlier: Such syntax is not universally recognized over all operating systems, or even all applications. And that's totally aside from the difficulty in user education.
For example, you'll probably have trouble getting a SSL
certificate.
Given that some CAs have already issued certs for host names that are not valid in the public DNS now, and have been doing so for years, dotless domains may have a higher barrier to entry for SSL, but the barrier is not infinitely high.
All that said, I am a proponent of the slightly heretical view that ICANN should not prohibit this for gTLDs, however I do think they should provide good user education as to why it will likely be a bad idea. The key factor for me is that the ccTLDs are already doing it, and there is nothing ICANN can do to stop them from doing so. Thus it would be "unfair" in a philosophical sense for ICANN to restrict the gTLDs in this manner. (I think one could even make an argument that for ICANN to attempt to do so would be restraint of trade, but IANAL.)
While I recognize that widespread use of dotless domains would undoubtedly break stuff in the short term, I also think that both application and OS developers would adapt to the changing landscape over time. It's also worth mentioning that at least some of the things that would "break" in the short term are things we've been telling people for many years not to do in the first place ...
Doug
which explains domains like 3com.net.
the trailing dot is not illegal.
Domain names can be presented with a trailing dot. A fully
qualified domain always contains at least one explicit dot.
The rightmost domain label of 3com.net. is "NET"; which does
not start with a digit, so that domain name is OK.
Although "3com.net" would not be a valid hostname; as a DNS name, it is fine.
If the definition of "FQDN" in some RFCs (Informational or not)
always included the trailing dot, I'd be inclined to agree with you.
But that's not the case, so protocol slots have been established for
"FQDNs" that are actually domains qualified relative to the root.
Since this ambiguity has been around since the very dawn of the DNS,
I suspect there is little chance of re-educating everyone in the
world about this.
I seem to recall back in the day being annoyed that some interfaces would not allow the trailing dot.
My failing memory does not provide and example.
(A test of Firefox and a URL I had just used, modified works. en.wikipedia.org./wiki/Server_Message_Block #)
A
After .nyc thread, thought this IAB announcement may be of
interest.IAB Statement: Dotless Domains Considered Harmful | Internet Architecture Board
-Jon
But not always at the end, which is why there's a problem. RFC1123, in my
opinion, contains a remark that ought to indicate to people that the
trailing dot convention isn't even universal for determining whether a name
is really fully-qualified. (See section 6.1.4.3. That RFC is also, of
course, how we got 3com.net as a legal name, for prior to 1123 "3com"
wasn't a valid label anywhere.)
Best,
A