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DNS record optimization
depricated
Member
in General
Are the DNS records created by cPanel necessary as is or can they be improved? In particular:
1) In addition to the domain name there are records for subdomains such as: cpanel, cpcalendars, cpcontacts, ftp, webdisk, webmail, whm, mail, www. Can/should this list be trimmed down?
2) Many of the above are A records with the domain's IP hard coded repeatedly. Could they all be converted to CNAME records, with just the domain having an A record with the IP?
Comments
mail. should never be a CNAME. Plenty of people do it, but you're not supposed to. I'm sure most are made A records for CPanel's code-reuse, so it doesn't have to parse the zone and figure out what to do when it can just do a regex sweep replace.
ftp/www/webmail should likely be left. I haven't used any of the others, but I bet there's an Outlook-like reason behind them.
That's funny. cPanel has mail. as CNAME by default for me.
CPanel never was very good at following directions. (10.3, fwiw)
In other words: cpanel has it reliably maximum idiotically wrong.
10.3 refers to MX records (which in cpanel lists the domain name as the destination). What is the difference between the MX and mail entries?
Seriously?
One is an A record, one is a CNAME. If you are using "mail.foo.org" as an MX record and MAIL points to a CNAME rather than an A record, you're doing it wrong.
Confused. "is a X record" and "points to a X record" mean different things to me.
Example of a setup:
MX record should not point to a CNAME, but something that resolves via A record; not that MX needs to be an IP address; an MX to name to CNAME to A record are recursive lookups. Everything pretty much handles it, but it's not what you're supposed to do. Like DNS glue, but without the glue.
@depricated
You can look at it like this: an MX record is meant for another machine (namely another mail server). So, whether it's called 'some-123-tech-taxonomy-456.some.dom' or 'smtp.some.dom' is meaningless. What, however, is meaningful is to keep the lookup short, simple, and efficient.
users and mail clients are a completely different thing. For them one usually wants something like 'mail.some.dom' - and that can be done without any problem because that's another "access path" to the mail server.
So you could and should do something like
Such, you have a cname free direct MX record and still a "friendly" cname to tell users to put into their email client config.
Thanks for the examples and explanation @bsdguy
I think the earlier posts were just a misunderstanding between "is" and "points to". What you described seems to be the same as cpanel's DNS configuration:
MX record which points to a server defined by an A record
mail is a CNAME record which points to a server defined by an A record
Note that there is also a "webmail" subdomain which a user can use to reach webmail. I don't know what "mail" is.
To answer my initial question, those automatically generated subdomains are apparently called proxy subdomains:
I have no plans to use cpcontacts, cpcalendars, webdisk, or whm (not reseller), but I guess I won't mess with them (for now..). Also I suppose there's a reason they are A records and not CNAME.
You're welcome.
Yeah but there's wrong and then there's what I'll call "nerd wrong." Does it work? Then it's fine. Whether or not you complied with every RFC will not generally be mentioned in your obituary.
The world isn't built on RFCs but the implementations and thus the interpretations of those who implemented them. That's what people (talking in the general sense in regards to RFC) have to strive to work with. Reality sucks. As does the use of "SHOULD" in RFCs.
MX record is not pointed to the mail CNAME, it points to the domain’s A record, so it’s done right.
Mail is used in configuration for mail clients.
Webmail is used to redirect to the cPanel Managed webmail System.
I don’t get this whole bitching on cPanel.
This was figured out several days ago, but thanks for weighing in.
No probs. :-)