Support » Networking WordPress » Domain Mapping Configuration: IP Adress -or- CNAME?

  • I am setting up the Domain Mapping Configuration and I have a choice of setting either.

    I was successful in using the IP. However, I am thinking that it may be easier future maintenance if I tell subsite admins to map using CNAME instead, so things are not hard-wired to a specific IP address.

    In trying to understand this better I am using a test subsite with DNS set up at Network solutions.

    It had 3 A records (for www, @ and *), each pointing to the IP address of my multisite. I went to add a CNAME for each and it told me that the A exists so it would not let me.

    So now I am deleting the A records in order to do the CNAME. Which means the site will appear broken in between the erase of the A records and the propagation of the CNAME…

    So I am thinking I may not be doing this right… any thoughts?

    Also, would it be sufficient for the CNAME to be mapped to the domain that is primary on my WP network or do I have to map it to some subdomain that has a A record pointing to the right IP address?

    Thanks for any insight!

Viewing 8 replies - 1 through 8 (of 8 total)
  • Moderator Ipstenu (Mika Epstein)


    Lead Plugin Wrangler

    Re-reading … I know less than I thought I did.

    I re-read the plugin info more recently also and what caught my eye this last time is:

    If your user is mapping a hostname of a domain (sometimes called a “subdomain”) like or it’s sufficient to create a CNAME record pointing at their blog url (NOT IP address).

    Particularly after not being able to, at the Registrar’s DNS setting panel, change the domain to point to my supersite-wp-network domain.

    It may be that you can use CNAME *only* for third level domains, such as or and you CANNOT DO CNAMES for second-level like pointing to the main supersite.

    I guess I’ll stick to using the IP….

    If you have interest in the topic, see my initial thread on the larger topic…

    The Domain Mapping plugin author replied but too succinctly to illuminate the topic completely, at least for me.

    Moderator Ipstenu (Mika Epstein)


    Lead Plugin Wrangler

    I’ll go ask him 🙂

    Andrea Rennick


    Customer Care at Copyblogger Media and Studiopress

    If you need to delete the A records before adding a CNAME, that’s more a question for your registrar. Doesn’t matter if you’re domain mapping or not.

    I’ve never had to delete one to use the other.

    CNAMES are generally in the format of

    Ron Rennick


    MultiSite Guru

    It may be that you can use CNAME *only* for third level domains, such as or and you CANNOT DO CNAMES for second-level like pointing to the main supersite.

    Some registrars permit CNAMES for TLDs and others do not. Godaddy does not. Namecheap does.

    Hey Ipstenu, I guess you weren’t kidding!

    OK, so my understanding is some registrars have limitation on CNAME not being avaialable for TLD.

    So the end user (subsite admin) will not be able to reliably set a CNAME for their website (at least if they don’t want http://www., such as that would allow them to map to their WP subsite (e.g.

    Assuming my understanding is correct, the super-admin should NOT use the CNAME option for Domain Mapping when setting the plugin. It can lead to the end user not being able to map the website they want to their subsite. We will have to hardwire to IP address. This will require the end user to use A records to map their domains (, to that IP address.

    I hope I got this right… just too important to screw this up.

    Thanks for your input on this; much appreciated.

    @andrea, to clarify the limitation I was encountering on the client’s registrar DNS setup screen…

    Trying to set up a CNAME for www. to go to, it was telling me that an A record exists for that subdomain (www). Based on that I assume that I need to delete the A record in order to let me do it.

    However, even after deleting, I still could not complete the setup (based on using the CNAME option) because the registrar would not let me create a CNAME for the base domain (to have – without the www subdomain – point to The ui has a field for the subdomain I want to create the CNAME for and it gives error if left empty. I tried using “@” but it only accepts alphanumeric, * and -.

Viewing 8 replies - 1 through 8 (of 8 total)
  • The topic ‘Domain Mapping Configuration: IP Adress -or- CNAME?’ is closed to new replies.