If your custom track domain uses a CNAME, some tracking blockers can recognize it as a Mapp domain and block your tracking requests. The data from these visitors never reaches Mapp Intelligence. Switching to an A-Record removes this weak point.
This article explains why the switch helps and what you need to consider. The general setup is described in Custom Track Domain.
Why CNAME Track Domains Get Blocked
With a CNAME, your track domain points to a Mapp domain. For the browser, the request still goes to your own domain. However, some tracking blockers resolve the DNS entry, find the Mapp domain behind it, and compare it with their block lists. If the Mapp domain is listed, they block your track domain as well, and your track domain can end up on block lists itself.
With an A-Record, your track domain points directly to the IP address of the Mapp tracking server. No Mapp domain appears in the DNS response, so this check finds nothing.
The effect: blocked requests lead to incomplete reports, fewer recognized visitors, and less reliable segments and personalization. You may not notice this in your reports, because blocked visits leave no trace. We therefore recommend switching even if you have not seen a drop in traffic.
Choose How to Switch
You can switch in two ways:
Keep your current track domain | Use a new track domain | |
|---|---|---|
What you do | Replace the CNAME of your current track domain with an A-Record and an AAAA-Record. | Set up a new subdomain with an A-Record and an AAAA-Record, then switch your tracking to it. |
Effort | Low. Tracking configuration and cookies stay unchanged. | Higher. You update your tracking configuration and may need to migrate cookies. |
When to use | Your current track domain is not yet blocked by name. | Your current track domain is already on block lists. Block lists that contain the name of your track domain keep blocking it, even after the DNS change. |
Your Mapp contact can help you decide.
Option 1: Keep Your Current Track Domain
Ask your Mapp contact for the IPv4 and IPv6 addresses of the Mapp tracking server.
With your DNS service provider, delete the CNAME of your track domain and create an A-Record and an AAAA-Record with these addresses. See step 4 in Custom Track Domain.
Check the new entries with
nslookup. The response must no longer contain a canonical name line.
Important
Only make the change if you have the correct addresses from Mapp. If the A-Record or AAAA-Record points to a wrong address, no tracking request reaches Mapp from that moment on.
Option 2: Use a New Track Domain
Step 1: Set Up the New Track Domain
Choose a new subdomain, for example dct.exampleshop.com instead of trk.exampleshop.com. Then follow steps 1 to 5 in Custom Track Domain. Mapp orders the SSL certificate for the new subdomain.
Step 2: Plan the Cookie Migration
If your tracking uses third-party cookies, they are tied to the previous track domain. Migrate them with the Cookie Control Plugin.
Without a cookie migration, returning visitors are counted as new visitors after the switch.
Step 3: Update Your Tracking Configuration
Replace the previous track domain with the new one in your tracking configuration. If Mapp has access to your setup, for example in Mapp Tag Integration, Mapp can make this change for you.
Step 4: Remove the Previous Track Domain
Keep the previous track domain active until no requests are sent to it anymore. This matters especially for mobile apps: older app versions keep sending to the previous track domain until users install the update. If you only track websites, you can usually remove it shortly after the switch.
When the previous track domain is no longer needed:
Tell your Mapp contact. Mapp removes the previous track domain from its servers.
Delete the previous CNAME entry with your DNS service provider.
Need Help?
Our service team supports you from the technical assessment to the full implementation. Contact your Customer Success Manager or open a request via the support portal.