Official bitly dns page:
On the Bitly Side:
1) This domain can only be used for your shortened URLs. Your short domain name needs to be 15 characters or less (including the dot).
2) Tell bitly about your domain. Sign in to your bitly account, go to ‘settings’ from the upper right pull-down menu and click on the ‘Advanced’ tab (or click here.)
Under ‘Custom Short Domain’ let us know if you plan to use your custom short domain for personal or business use. Or just click here. If you are business, fill out a brief survey for our enterprise team. If the domain is for personal use, you can add your custom short domain in the text box provided. Note: you will need to verify your email address to take this step. You can do that here.
|point A-record (IP address)|
|THREE OR MORE LEVELS
(E.G. WWW.MYWEBSITE.COM OR BLOG.MYWEBSITE.COM)
|point CNAME record to “cname.bitly.com”|
On the Dreamhost Side:
From the panel, Go to your Manage Domains Page and make sure the domain is DNS only. If you have hosting on the domain, use the “remove” button under the “web hosting” column:
Once the domain is dns only, click the dns link under your domain name and add these records:
Custom DNS Options:
Name: subdomain, leave blank for naked/root domain
Type: type of dns record, such as A record, Cname, TXT
Settings Needed for this setup:
Name: leave blank for naked/root domain
Value: IP RECORD
Note: This guide has been created to help simplify setting your domain up. The service you are pointing your domain to, DNS can/might has changed. Always check the hosts official page to verify the records.