CNAME Warning

When using a DNS Report tool at this site: http://www.dnsreport.com/

I get a few “FAIL” and many “WARNINGS”, one being the following on ALL my sites created via Interworx:

“CNAME Lookup”

“WARNING. Your web site (www.mywebsite.com) has a CNAME record pointing to mywebsite.com… That by itself is confusing, but acceptable. However, the CNAME record in this case causes an extra DNS lookup, which will slightly delay visitors to your website, and use extra bandwidth.”

Please explain why a CNAME record is created poiting to the same domain, and why this DNS report says it is unnecessary.

Thanks.

I have now delete above mentioned redundant CNAME record on a test site, to see what happens.

I probably have to wait about 43200 seconds, before seeing chances, if any though :slight_smile:

RWF, DNS report explains it itself. It causes a 2nd DNS lookup. If you’d rather just make an A record doing the same thing that the CNAME is.

Chris

This is one area I am 200% confused on, DNS, A records, and Name Servers. I don’t know what an A record is, and I blindly trust in Interworx to set it up right.

Let me rephrase my question.

Do I need the CNAME for www.mywebsite.com and ftp.mywebsite.com.

Why do or why do I not?

Why do they say it is redundant and I can save access time by eliminating it, and if so why did Interworx create it.

I would have loved if there some detailed popup help screen for the different type of records.

An A record maps a host name to an IP address. A CNAME reccord maps a host name to another host name, which then must be mapped to an IP address.

This is a cleanlyness issue. You could use a straight A record, but in case your IP address ever changes, you may want the CNAME record intsead. Its cleaner should something change.

Its really not anything worth worrying about. All these DNS warnings and fails you are talking about really aren’t signifigant and won’t hurt a thing.

So in other words, since I have a static IP, I can safely delete both (ftp and www) CNAME entries on all my sites?

Almost. You can safely delete the CNAME entries and replace them with matching A records, but I personaly wouldn’t advise it. The IWorx guys chose to do things this way for probably more reasons than I can think of. After being both a Nexcess.net web hosting customer and InterWorx customer (well, I admin the box) I trust that they’ve done things right.

I suppose its kind of silly to blindly trust someone else’s judgement, but they haven’t let me down yet.

Host: [?] Type: [?] Target: [?] TTL: [?]
mail.my.transwarphosting.net A 207.150.160.102 43200
my.transwarphosting.net A 207.150.160.102 43200
ftp.my.transwarphosting.net CNAME my.transwarphosting.net 43200
www.my.transwarphosting.net CNAME my.transwarphosting.net 43200
my.transwarphosting.net NS ns1.transwarphosting.net 43200
my.transwarphosting.net NS ns2.transwarphosting.net 43200
my.transwarphosting.net NS ns3.transwarphosting.net 43200
mail.my.transwarphosting.net MX 10 43200
my.transwarphosting.net SOA Edit SOA Properties 43200

This is an example of what I have on my.transwarphosting.net (transwarphosting.net has several subdomains and exgra cname records that would be confusing so I used this one).

If you delete the extra CNAME records you will no longer be able to access your site from ftp.mysite.com and the mail.mysite.com is because moste of your users use that for a mail server setting. Removing the CNAME records will break that.

If you use the IP for these things than you can remove them but it may confuse other site users.