what's a valid domain name?
Ben Croswell writes: > In that case technically you are creating undelegated subdomains for each > router. > The dot is a delimiter and can't be part of a hostname. > I was thinking you are wrong. Period is somewhat permitted in a hostname. Kristen Eisenberg Billige Flüge Marketing GmbH Emanuelstr. 3, 10317 Berlin Deutschland Telefon: +49 (33) 5310967 Email: utebachmeier at gmail.com Site: http://flug.airego.de - Billige Flüge vergleichen___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
what's a valid domain name?
I googled and found this: * A domain name can be up to 63 characters long plus a dot plus the characters used to identify the top-level domain (i.e "com", "info", "biz", etc. * Valid characters in a domain name include letters, numbers and hyphens "-". The domain name must start and end with a letter or number. So, for this domain name of "www.xyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxy.com" whose size is larger than 64, is not a valid domain name? And is there a RFC item for a valid domain name? Regards. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
Actually a . is not part of a host name. It separates all the parts of FQDN. If you put one in a host name you have an undelegated subdomain as I stated before. -Ben Croswell On Oct 31, 2011 6:59 AM, "Kristen Eisenberg" wrote: > Ben Croswell writes: > > > In that case technically you are creating undelegated subdomains for each > > router. > > The dot is a delimiter and can't be part of a hostname. > > > > I was thinking you are wrong. > Period is somewhat permitted in a hostname. > > Kristen Eisenberg > Billige Flüge > Marketing GmbH > Emanuelstr. 3, > 10317 Berlin > Deutschland > Telefon: +49 (33) > 5310967 > Email: > utebachmeier at > gmail.com > Site: > http://flug.airego.de - Billige Flüge vergleichen > > ___ > Please visit https://lists.isc.org/mailman/listinfo/bind-users to > unsubscribe from this list > > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users > ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
On 10/31/2011 6:58 AM, Kristen Eisenberg wrote: Ben Croswell writes: > In that case technically you are creating undelegated subdomains for each > router. > The dot is a delimiter and can't be part of a hostname. > I was thinking you are wrong. Period is somewhat permitted in a hostname. People are using "hostname" to mean different things. If "hostname" is interpreted to mean "the string that one device uses to represent another so that the two of them can communicate", then obviously whether dots are permitted in hostnames, will depend wholly on what mechanism translates the string into a network address: if the mechanism is DNS, or an /etc/hosts file, then dots are permitted in the string; in the case of other name-resolution mechanisms (e.g. NetBIOS name resolution?), dots may or may not be supported. If, on the other hand, "hostname" is interpreted to mean "everything preceding the first dot in the standard representation of the network entity", then by definition such a "hostname" will not, and cannot contain a dot. - Kevin ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
In article , p...@mail.nsbeta.info wrote: > I googled and found this: It's on the Internet, so it must be true. :) > > * A domain name can be up to 63 characters long plus a dot plus the > characters used to identify the top-level domain (i.e "com", "info", "biz", > etc. > * Valid characters in a domain name include letters, numbers and > hyphens "-". The domain name must start and end with a letter or number. > > > So, for this domain name of > "www.xyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxy.com" > whose size is larger than 64, is not a valid domain name? > > And is there a RFC item for a valid domain name? RFC 1035 section 3.1 says: "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." The length of each label within a domain name is limited to 63 characters. -- Barry Margolin, bar...@alum.mit.edu Arlington, MA *** PLEASE don't copy me on replies, I'll read them in the group *** ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
Barry Margolin writes: In article , p...@mail.nsbeta.info wrote: I googled and found this: It's on the Internet, so it must be true. :) * A domain name can be up to 63 characters long plus a dot plus the characters used to identify the top-level domain (i.e "com", "info", "biz", etc. * Valid characters in a domain name include letters, numbers and hyphens "-". The domain name must start and end with a letter or number. So, for this domain name of "www.xyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxy.com" whose size is larger than 64, is not a valid domain name? And is there a RFC item for a valid domain name? RFC 1035 section 3.1 says: "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." The length of each label within a domain name is limited to 63 characters. Thanks for the kind info. Regards. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
In message <20110129053051.bad452d...@mail.nsbeta.info>, p...@mail.nsbeta.info w rites: > Barry Margolin writes: > > > In article , > > p...@mail.nsbeta.info wrote: > > > >> I googled and found this: > > > > It's on the Internet, so it must be true. :) > > > >> > >> * A domain name can be up to 63 characters long plus a dot plus the > >> characters used to identify the top-level domain (i.e "com", "info", "biz" > , > >> etc. > >> * Valid characters in a domain name include letters, numbers and > >> hyphens "-". The domain name must start and end with a letter or number. > >> > >> > >> So, for this domain name of > >> "www.xyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxyxy.com" > > >> whose size is larger than 64, is not a valid domain name? > >> > >> And is there a RFC item for a valid domain name? > > > > RFC 1035 section 3.1 says: "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." > > > > The length of each label within a domain name is limited to 63 > > characters. > > > > Thanks for the kind info. Remember domain names are not the same things as hostnames. Hostnames are limited to letter digit hyphen (LDH). Other domain names are not limited and things last SRV records deliberately use labels that are not legal in hostnames to prevent collisions of the two namespaces when they are stored in the DNS. > Regards. > ___ > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
As noted before, RFC 1035 set some specifications. But there were a number of clarifications and changes, notably RFC 1123 and RFC 2181. So, Pyh, your quote is not quite correct today. The first part never was - it only refers to second-level domains. The second part is correct for hostnames only. RFC 1035: ::= [ [ ] ] ::= | ::= | "-" ::= | ::= any one of the 52 alphabetic characters A through Z in upper case and a through z in lower case ::= any one of the ten digits 0 through 9 Note that while upper and lower case letters are allowed in domain names, no significance is attached to the case. That is, two names with the same spelling but different case are to be treated as if identical. The labels must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen. There are also some restrictions on the length. Labels must be 63 characters or less. [Joe note: but see RFC 1123 below.] RFC 1123: 2.1 Host Names and Numbers The syntax of a legal Internet host name was specified in RFC-952 [DNS:4]. One aspect of host name syntax is hereby changed: the restriction on the first character is relaxed to allow either a letter or a digit. Host software MUST support this more liberal syntax. Host software MUST handle host names of up to 63 characters and SHOULD handle host names of up to 255 characters. RFC 2181: 11. Name syntax Occasionally it is assumed that the Domain Name System serves only the purpose of mapping Internet host names to data, and mapping Internet addresses to host names. This is not correct, the DNS is a general (if somewhat limited) hierarchical database, and can store almost any kind of data, for almost any purpose. The DNS itself places only one restriction on the particular labels that can be used to identify resource records. That one restriction relates to the length of the label and the full name. The length of any one label is limited to between 1 and 63 octets. A full domain name is limited to 255 octets (including the separators). The zero length full name is defined as representing the root of the DNS tree, and is typically written and displayed as ".". Those restrictions aside, any binary string whatever can be used as the label of any resource record. Similarly, any binary string can serve as the value of any record that includes a domain name as some or all of its value (SOA, NS, MX, PTR, CNAME, and any others that may be added). Implementations of the DNS protocols must not place any restrictions on the labels that can be used. In particular, DNS servers must not refuse to serve a zone because it contains labels that might not be acceptable to some DNS client programs. A DNS server may be configurable to issue warnings when loading, or even to refuse to load, a primary zone containing labels that might be considered questionable, however this should not happen by default. Note however, that the various applications that make use of DNS data can have restrictions imposed on what particular values are acceptable in their environment. For example, that any binary label can have an MX record does not imply that any binary name can be used as the host part of an e-mail address. Clients of the DNS can impose whatever restrictions are appropriate to their circumstances on the values they use as keys for DNS lookup requests, and on the values returned by the DNS. If the client has such restrictions, it is solely responsible for validating the data from the DNS to ensure that it conforms before it makes any use of that data. See also [RFC1123] section 6.1.3.5. [Joe note: I think the section number is incorrect.] -- /*\ ** ** Joe Yao j...@tux.org - Joseph S. D. Yao ** \*/ ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
Mark Andrews writes: Remember domain names are not the same things as hostnames. Hostnames are limited to letter digit hyphen (LDH). Other domain names are not limited and things last SRV records deliberately use labels that are not legal in hostnames to prevent collisions of the two namespaces when they are stored in the DNS. Could you show an example for the difference between a hostname and a domain name? Thanks again. Regards. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
Joseph S D Yao writes: The labels must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen. There are also some restrictions on the length. Labels must be 63 characters or less. A label must start with a letter? oh I don't think so. How about these domains which all have huge DNS traffic? 163.com 126.com 51.com 56.com yes 163.com is a domain name but "163" also can be treated as a label for domain "com.", is it? Thanks. Regards. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
In message <20110130013241.dff772d...@mail.nsbeta.info>, p...@mail.nsbeta.info wri tes: > Mark Andrews writes: > > > > Remember domain names are not the same things as hostnames. Hostnames > > are limited to letter digit hyphen (LDH). Other domain names are not > > limited and things last SRV records deliberately use labels that are > > not legal in hostnames to prevent collisions of the two namespaces when > > they are stored in the DNS. > > > > Could you show an example for the difference between a hostname and a > domain name? _http._srv.example.com is not a hostname but is a domain name. example.com is a hostname and a domain name. > Thanks again. > > Regards. -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
From RFC 1123 One aspect of host name syntax is hereby changed: the restriction on the first character is relaxed to allow either a letter or a digit. Host software MUST support this more liberal syntax. p...@mail.nsbeta.info writes: Joseph S D Yao writes: The labels must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen. There are also some restrictions on the length. Labels must be 63 characters or less. A label must start with a letter? oh I don't think so. How about these domains which all have huge DNS traffic? 163.com 126.com 51.com 56.com yes 163.com is a domain name but "163" also can be treated as a label for domain "com.", is it? Thanks. Regards. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
Correct, the requirement to start with a letter was removed ages ago. Witness 3com.com, which may have been the first. Chris Buxton BlueCat Networks On 1/29/11, p...@mail.nsbeta.info wrote: > Joseph S D Yao writes: > >> >> The labels must follow the rules for ARPANET host names. They must >> start with a letter, end with a letter or digit, and have as interior >> characters only letters, digits, and hyphen. There are also some >> restrictions on the length. Labels must be 63 characters or less. >> > > A label must start with a letter? oh I don't think so. > How about these domains which all have huge DNS traffic? > > 163.com > 126.com > 51.com > 56.com > > yes 163.com is a domain name but "163" also can be treated as a label for > domain "com.", is it? > > Thanks. > > Regards. > ___ > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users > -- Sent from my mobile device ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
In article , Chris Buxton wrote: > Correct, the requirement to start with a letter was removed ages ago. > Witness 3com.com, which may have been the first. Yes, I'm pretty sure they were the impetus for the change, paving the way for 1-800-FLOWERS.COM years later. -- Barry Margolin, bar...@alum.mit.edu Arlington, MA *** PLEASE don't copy me on replies, I'll read them in the group *** ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
What is the status of "dotted" hostnames - i.e. a period in the hostname portion of a domain name ? At one point they were allowed, I believe ? What is the latest official RFC ? Thanks... Vyto - Original Message - From: Barry Margolin Date: Sunday, January 30, 2011 3:34 pm Subject: Re: what's a valid domain name? To: comp-protocols-dns-b...@isc.org > In article , > Chris Buxton wrote: > > > Correct, the requirement to start with a letter was removed ages ago. > > Witness 3com.com, which may have been the first. > > Yes, I'm pretty sure they were the impetus for the change, paving the > > way for 1-800-FLOWERS.COM years later. > > -- > Barry Margolin, bar...@alum.mit.edu > Arlington, MA > *** PLEASE don't copy me on replies, I'll read them in the group *** > ___ > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users > ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
In article , Vytautas Grigaliunas wrote: > What is the status of "dotted" hostnames - i.e. a period in the hostname > portion of a domain name ? > > At one point they were allowed, I believe ? What is the latest official RFC ? I don't think they've every been allowed. Why would you need to do this, instead of just using another level of subdomain? To get a literal period into a label, you need to escape it, e.g. foo\.bar.company.com instead of foo.bar.company.com. The latter is allowed, always has been, and is quite common. -- Barry Margolin, bar...@alum.mit.edu Arlington, MA *** PLEASE don't copy me on replies, I'll read them in the group *** ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
On Jan 30, 2011, at 1:47 PM, Vytautas Grigaliunas wrote: > What is the status of "dotted" hostnames - i.e. a period in the hostname > portion of a domain name ? > > At one point they were allowed, I believe ? What is the latest official RFC ? Periods, or dots, act as dividers in a domain name, separating the various labels. You may have a 'dotted host' in any zone you control. For example, if you control example.com, then some.host.example.com is a valid record name within that zone, as long as host.example.com is not delegated as a subzone. Chris Buxton BlueCat Networks ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
RE: what's a valid domain name?
Although we're moving away from it, we found it useful for naming router interfaces, i.e. te1-2.routername.company.com, without having to create a separate sub-domain for each router. I thought at some point periods were allowed in hostnames, and they do work without escaping them. Thanks... Vyto > -Original Message- > From: bind-users-bounces+vyto=fnal@lists.isc.org [mailto:bind- > users-bounces+vyto=fnal@lists.isc.org] On Behalf Of Barry Margolin > Sent: Sunday, January 30, 2011 4:14 PM > To: comp-protocols-dns-b...@isc.org > Subject: Re: what's a valid domain name? > > In article , > Vytautas Grigaliunas wrote: > > > What is the status of "dotted" hostnames - i.e. a period in the > hostname > > portion of a domain name ? > > > > At one point they were allowed, I believe ? What is the latest > official RFC ? > > I don't think they've every been allowed. Why would you need to do > this, instead of just using another level of subdomain? To get a > literal period into a label, you need to escape it, e.g. > foo\.bar.company.com instead of foo.bar.company.com. The latter is > allowed, always has been, and is quite common. > > -- > Barry Margolin, bar...@alum.mit.edu > Arlington, MA > *** PLEASE don't copy me on replies, I'll read them in the group *** > ___ > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
Vyto, "Dotted hostnames" is a term coined by certain limited DNS-management tools that strive to split up fully-qualified DNS names into a "hostname" part and a "zone" (sometimes referred to as "domain") part. If one chooses to extend a given name for 2 or more labels below the closest-enclosing zone cut, then in the standard representation used by those tools, the "hostname" portion of the name will have a dot in it, hence "dotted hostnames", which are treated by such limited tools as somehow weird and special. At least one tool I'm familiar with, requires a special non-default option setting to even allow "dotted hostnames" to exist at all in its database. DNS itself has never had a problem with multiple labels beneath a zone cut. Better tools recognize the inherent flexibility of DNS naming and don't try to deprecate or otherwise discourage so-called "dotted hostnames". - Kevin On 1/31/2011 10:50 AM, Vyto Grigaliunas wrote: Although we're moving away from it, we found it useful for naming router interfaces, i.e. te1-2.routername.company.com, without having to create a separate sub-domain for each router. I thought at some point periods were allowed in hostnames, and they do work without escaping them. Thanks... Vyto -Original Message- From: bind-users-bounces+vyto=fnal@lists.isc.org [mailto:bind- users-bounces+vyto=fnal@lists.isc.org] On Behalf Of Barry Margolin Sent: Sunday, January 30, 2011 4:14 PM To: comp-protocols-dns-b...@isc.org Subject: Re: what's a valid domain name? In article, Vytautas Grigaliunas wrote: What is the status of "dotted" hostnames - i.e. a period in the hostname portion of a domain name ? At one point they were allowed, I believe ? What is the latest official RFC ? I don't think they've every been allowed. Why would you need to do this, instead of just using another level of subdomain? To get a literal period into a label, you need to escape it, e.g. foo\.bar.company.com instead of foo.bar.company.com. The latter is allowed, always has been, and is quite common. -- Barry Margolin, bar...@alum.mit.edu Arlington, MA *** PLEASE don't copy me on replies, I'll read them in the group *** ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
Ben Croswell writes: In that case technically you are creating undelegated subdomains for each router. The dot is a delimiter and can't be part of a hostname. I was thinking you are wrong. Period is somewhat permitted in a hostname. From RFC 952 A "name" (Net, Host, Gateway, or Domain name) is a text string up to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus sign (-), and period (.). Note that periods are only allowed when they serve to delimit components of "domain style names". No blank or space characters are permitted as part of a name. No distinction is made between upper and lower case. The first character must be an alpha character [Relaxed in RFC 1123] . The last character must not be a minus sign or period. regrads. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
In article , Vyto Grigaliunas wrote: > Although we're moving away from it, we found it useful for naming router > interfaces, i.e. te1-2.routername.company.com, without having to create a > separate sub-domain for each router. > > I thought at some point periods were allowed in hostnames, and they do work > without escaping them. I think you're confusing subdomain and subzone. You can have subdomains without having subzones. E.g. in the company.com zone file, you can put: te1-2.routername IN A 1.2.3.4 -- Barry Margolin, bar...@alum.mit.edu Arlington, MA *** PLEASE don't copy me on replies, I'll read them in the group *** ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
The rfc you quote clearly states when used as a delimiter of a domain as I stated. -Ben Croswell On Jan 31, 2011 8:58 PM, wrote: > Ben Croswell writes: > >> In that case technically you are creating undelegated subdomains for each >> router. >> The dot is a delimiter and can't be part of a hostname. >> > > I was thinking you are wrong. > Period is somewhat permitted in a hostname. > > From RFC 952 > > A "name" (Net, Host, Gateway, or Domain name) is a text string up > to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus > sign (-), and period (.). Note that periods are only allowed when > they serve to delimit components of "domain style names". > > No blank or space characters are permitted as part of a > name. No distinction is made between upper and lower case. The first > character must be an alpha character [Relaxed in RFC 1123] . The > last character must not be a minus sign or period. > > > regrads. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
On Sun, Jan 30, 2011 at 09:40:51AM +0800, p...@mail.nsbeta.info wrote: > Joseph S D Yao writes: > > > > > The labels must follow the rules for ARPANET host names. They must > > start with a letter, end with a letter or digit, and have as interior > > characters only letters, digits, and hyphen. There are also some > > restrictions on the length. Labels must be 63 characters or less. > > > > A label must start with a letter? oh I don't think so. > How about these domains which all have huge DNS traffic? > > 163.com > 126.com > 51.com > 56.com > > yes 163.com is a domain name but "163" also can be treated as a label for > domain "com.", is it? That's why I said it was modified later. Did you read the whole message I wrote? I spent hours slaving over a hot bit-griddle just to make it for you. -- /*\ ** ** Joe Yao j...@tux.org - Joseph S. D. Yao ** \*/ ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
To add to the story, I added a rule to our DNS administration system that we'll only allow hostnames that include at least one alphabetic. John On Feb 4, 2011, at 11:26 AM, John Wobus wrote: So 10.14.22.11 is a legal hostname, right? We had a recent experience where our DNS administration system allowed someone to insert in a CNAME record that resembled this: www.example.com. CNAME 10.14.22.11. A fascinating thing about this is that my computer/browser could take me to www.example.com just fine. John Wobus Cornell On Jan 30, 2011, at 7:30 AM, p...@mail.nsbeta.info wrote: From RFC 1123 One aspect of host name syntax is hereby changed: the restriction on the first character is relaxed to allow either a letter or a digit. Host software MUST support this more liberal syntax. p...@mail.nsbeta.info writes: Joseph S D Yao writes: The labels must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen. There are also some restrictions on the length. Labels must be 63 characters or less. A label must start with a letter? oh I don't think so. How about these domains which all have huge DNS traffic? 163.com 126.com 51.com 56.com yes 163.com is a domain name but "163" also can be treated as a label for domain "com.", is it? Thanks. Regards. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
So 10.14.22.11 is a legal hostname, right? We had a recent experience where our DNS administration system allowed someone to insert in a CNAME record that resembled this: www.example.com. CNAME 10.14.22.11. A fascinating thing about this is that my computer/browser could take me to www.example.com just fine. John Wobus Cornell On Jan 30, 2011, at 7:30 AM, p...@mail.nsbeta.info wrote: From RFC 1123 One aspect of host name syntax is hereby changed: the restriction on the first character is relaxed to allow either a letter or a digit. Host software MUST support this more liberal syntax. p...@mail.nsbeta.info writes: Joseph S D Yao writes: The labels must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen. There are also some restrictions on the length. Labels must be 63 characters or less. A label must start with a letter? oh I don't think so. How about these domains which all have huge DNS traffic? 163.com 126.com 51.com 56.com yes 163.com is a domain name but "163" also can be treated as a label for domain "com.", is it? Thanks. Regards. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: what's a valid domain name?
On Fri, Feb 04, 2011 at 11:26:08AM -0500, John Wobus wrote: > So 10.14.22.11 is a legal hostname, right? > > We had a recent experience where our DNS administration > system allowed someone to insert in a CNAME record that > resembled this: > > www.example.com. CNAME 10.14.22.11. > > A fascinating thing about this is that my computer/browser could > take me to www.example.com just fine. I'm guessing that someone stuck records like: 10.14.22.11 A 10.14.22.11 in your system at Cornell? Otherwise, normally, the CNAME record above would cause errors (i.e., if "10.14.22.11" were not a name, as well). You can't check this with 'nslookup' - you need to use 'dig'. [Nobody need respond with the well-known merits and failings of 'nslookup'.] -- /*\ ** ** Joe Yao j...@tux.org - Joseph S. D. Yao ** \*/ ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: RE: what's a valid domain name?
In that case technically you are creating undelegated subdomains for each router. The dot is a delimiter and can't be part of a hostname. -Ben Croswell On Jan 31, 2011 11:19 AM, "Vyto Grigaliunas" wrote: ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
