|WikiProject Computing / Networking||(Rated Start-class, Low-importance)|
|WikiProject Internet||(Rated Start-class, Low-importance)|
The description of DNAME is unfortunately completely wrong.
DNAME only redirects subdomains.
The DNAME example suggests the principle stated above, when it says that an A-lookup for foo fails. That contradicts the assertion in the main paragraph, which says that a "DNAME maps a domain and it's subdomains". Change that to simple "subdomains", and it's accurate. I am about to make that change, after seeing the confirmation above. (I am not adding the part about CNAME and DNAME not allowed for the same node, although possibly I should.) 18.104.22.168 (talk) 17:48, 5 November 2010 (UTC)
The best use of DNAME that never was:
ip6.int. IN DNAME ip6.arpa.
CNAME wording nit, details section
Suggest changing the wording: "CNAME must have no other resource records of other types" to something like "a node with a CNAME record must have no other resource records". Current wording makes it sound as if the CNAME record itself could have a record, or as if a node could have more than one CNAME record, neither of which is the case, AFAIK. Chconnor (talk) 02:27, 14 November 2010 (UTC)
I agree; the sentence in confusing. As someone trying to learn DNS better, this sentence makes me ask "What does 'have' mean? ...reference? ...be used in?". And my wording nit: if "other" is really needed twice, change one to "different".
Would it be correct to say "An alias defined by a CNAME record should not be used in resource records of other types (SOA, NS, MX, A, etc)."? Pbyhistorian (talk) 18:45, 23 October 2011 (UTC)
- The canonical name itself must be defined by a record other than a CNAME or DNAME record.
- The canonical name itself must be defined by another record.
- It's a while since I've looked at this, but my recollection is that the other record cannot be a CNAME or DNAME, so doesn't that need to be mentioned? I take the point that in a big-picture sense, the proposed wording is correct and simpler (which is good), but perhaps needs the qualification. Johnuniq (talk) 22:43, 11 March 2011 (UTC)
The expression "The canonical name itself must be defined by a record other than..." is likely understood as forbidding using a CNAME record with a canonical name. If the subsequent clarification "CNAME records that point to other CNAME records ... are not an error" is correct, I suggest altering the first statement from "must be" to "is usually". — Preceding unsigned comment added by 22.214.171.124 (talk) 16:26, 11 May 2012 (UTC)
Conflicting A and CNAME records — precedence?
Consider the following DNS setup:
www.example.com. IN A 126.96.36.199 *.example.com. IN CNAME www.google.com
- The first line signifies that www.example.com shall point to IP address 188.8.131.52, the IP address of the IANA example HTTP server.
- The second line signifies that any subdomain in example.com, including the www subdomain, shall point to www.google.com.
- This is a good question. I can't believe this Talk page has not been visited by an expert in five years! David Spector (talk) 13:20, 24 October 2017 (UTC)
- 2.4 CNAME records
- A CNAME record is not allowed to coexist with any other data. In other words, if suzy.podunk.xx is an alias for sue.podunk.xx, you can't also have an MX record for suzy.podunk.edu, or an A record, or even a TXT record.
CNAMEs using identifiers as alias URIs
In the authoritative DNS zones for my websites, my hosting company has frequently used identifiers as alias URIs.
Here are some examples:
springtimesoftware.com. A 184.108.40.206
www CNAME springtimesoftware.com.
ftp CNAME springtimesoftware.com.
In a browser, the URL springtimesoftware.com. is directly translated to IP address 220.127.116.11, but the first CNAME record makes this also true for URL www.springtimesoftware.com. Using FTP, a hostname ftp.springtimesoftware.com will also be translated to 18.104.22.168.
So the record "www CNAME springtimesoftware.com." appears to be treated exactly like "www.springtimesoftware.com. CNAME springtimesoftware.com.".
This article (and other articles on the Web) fail to describe this case of using an identifier (such as www or ftp) as the alias name in a CNAME record.