Posterous added the ability to have a custom domain point to your posterous blog back in summer 2008. To setup your domain with posterous is relatively simple. You need to go to your posterous settings for your blog, and add your domain in the “Custom domain name” text box in the “Addresses and such” section. Then it is necessary to go to your DNS host for your domain (quite often this is hosted by the company you registered your domain with), and add “A type” records for your root domain, and the “www” prefix if you want that to forward as well. In my case the registrar I used for zittlau.ca does not provide DNS services, so the use of a third-party DNS service was required.
I had previously been using editdns’s free DNS service, but due to recent DDOS attacks they have decided to limit the free services that they will be continuing to provide. Fortunately the same week as this announcement there happened to be a deal on dreamhost to get one year of hosting, including a domain registration for ~$10. I jumped on the opportunity to move my DNS over to dreamhost, and get the additional benefit of a proxy which I can use to listen to pandora/last.fm from Canada by appearing to be in the US (I’ll make a post about this later).
I unfortunately ran into some issues when I attempted to configure the DNS to forward to posterous. Dreamhost had already assigned A type records to point to their own server as “Non-editable”. When I attempted to added A type entries to point to the posterous IP (67.207.139.81), zittlau.ca worked correctly and forwarded to posterous, but www.zittlau.ca would not forward. Doing some checking using nslookup, I discovered that zittlau.ca had setup my custom IP as it’s primary DNS entry, but that www.zittlau.ca was still using the dreamhost webhost as the primary IP address, and my custom IP as the secondary.
Through some searching I was able to figure out that what I needed to do to remove the web hosting from the domain in Dreamhost. I’ve attached an image that shows the somewhat scary “Delete” button that needs to be clicked to accomplish this. Be careful following this procedure if you already host a website at your domain on Dreamhost. It is possible that clicking this button could delete your files from dreamhosts server, so make sure you back them up first! If you’re like me and have just moved to dreamhost, or are adding a new domain that doesn’t have a site yet built for it, then you are free to go ahead and click that button.
Clicking this button dreamhost removes the web services from the domain, along with the “Non-editable” DNS entries that are likely causing conflicts. At this point you should be able to go add A type entries to point to the posterous IP for both the www subdomain, as well as the root domain. Without the web hosting and the “Non-editable” A records, these should now become the primary DNS resolved IP addresses so that users will be forwarded to your posterous when they visit them (once a few hours have passed for the DNS changes to propagate).
After following this procedure, now the nslookups for both zittlau.ca and www.zittlau.ca resolve to the expected posterous IP (67.207.139.81), and my domain behaves as expected, forwarding users to my posterous blog.
