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I have a domain set with a CNAME alias to point to Heroku, but it is not resolving.

Here is a link to a screenshot:

And here is the output from nslookup:

$ nslookup -query=any
Address:        nameserver =
        primary name server =
        responsible mail addr =
        serial  = 2002050701
        refresh = 10800 (3 hours)
        retry   = 3600 (1 hour)
        expire  = 604800 (7 days)
        default TTL = 3600 (1 hour)        nameserver =        MX preference = 5, mail exchanger =        MX preference = 5, mail exchanger =        MX preference = 5, mail exchanger =        nameserver =        nameserver =        nameserver =  internet address =  internet address =  internet address =  internet address =  internet address =

Here is the destination host:

$ nslookup
Non-authoritative answer:


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migrated from Jan 10 '14 at 0:27

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1 Answer 1

up vote 3 down vote accepted

If you have a CNAME alias then you must not have other DNS records (e.g., NS) for that name - see rfc1912 - section 2.4.

I guess that eNom interface just filters out this "CNAME for the whole domain". You must point your root domain name to IP addresses (or make the operator of .ac add a CNAME in their records - probably impossible).

If you use Amazon services, then this information about Amazon Route53 and its alias extension might also be interesting for you (see number 3).

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Heroku doesn't support A name records.…. They only support using CNAME aliases, and ENom appears to support CNAME for root domains. I am guessing they emulate it or something. When I had CNAME pointed to the non-SSL Heroku server, it was working fine. – Chloe Jan 9 '14 at 22:44
Here is more about Heroku and root domains. "Zone apex domains (aka “naked”, “bare” or “root” domains), e.g.,, using conventional DNS A-records are not supported on Heroku." And more: – Chloe Jan 9 '14 at 22:47
If DNS provider allow aliasing of root domain then they usually use special record name for this (alias as Route53 or something like this as heroku say here:… ). If ENom support just CNAME and you have other domains with same configuration that just works then maybe they emulate this by scripting and not serve multiple IP for heroku? Can you give me a domain name on ENom with CNAME for root and rest of record similar to this one? – dsznajder Jan 9 '14 at 23:04
Ok I turned off mail forwarding (I needed it to get my SSL) and set and reset the A and CNAME records and now it is working! – Chloe Jan 10 '14 at 0:59

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