We've had some issues with our domain provider (1&1) automatically resetting our CNAME record for a subdomain (which is www.).

I've spoken to them about this and they say they're resetting it because it's "inadvisable" to have a CNAME on a www subdomain, stating that Tim Berners Lee designed it to only be used with the root. This is news to me. As I understand it, there is nothing special about the www subdomain in a technological sense.

It may be unusual, but in our case its use with a CNAME is very deliberate. Is it actually breaking some technological best practice?

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    It's news to me too that Tim Berners-Lee was even involved in designing the DNS system ... Mar 3, 2018 at 3:45

2 Answers 2


Barring unusual behavior from a web-browser or poorly coded application, there's nothing special about the www domain. I would suggest looking for a new DNS provider if they're willing to change DNS records without your approval or your knowledge.

  • It's 1&1. We only use them for domain hosting. It took an hour on the phone for them to remove this "feature" from our account. Crazy. Mar 2, 2018 at 19:48
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    @DjangoReinhardt You've been given great advice here I hope you follow - get away from any vendor that does stuff like this, ASAP.
    – ceejayoz
    Mar 2, 2018 at 22:13

If they're setting it to the same IP as the domain's main A or AAAA record, this may just be a kludgy attempt at CNAME flattening. If they're parking it or setting it to a different end IP, then that's clear abuse.

For what it's worth, lots of sites use www CNAMEs pointing to the @ A record. cPanel actually usually sets that by default, so you only have to update your @ A or @ AAAA record once. And given the amount of caching present in DNS, there's not a real, tangible performance tax or benefit being incurred here unless you have a particularly bad DNS implementation.

Reality is that, CNAME or not, you're eventually ending up with an IP address, and it will end up being cached somewhere. So I recommend finding a DNS vendor that doesn't try meddling with your records for some holier-than-thou reason.


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