# A record
The A record is a solution for tracking purposes using 1st party cookies.\
You need to combine A record with the [CAID on-premise cookie](/configure/administration/domain-management/cookie-caid.md) to get the most out of it.
## What is a `A record?`
A record (A for Address) is a DNS record type. It is a match between a domain and an IP address. It points the hostname to the IP address.
cs.example.com ⇒ IP Address : 36.283.49.384
## How the A record creation process works
Since there is a link between the domain and the IP address, we need to have control over it. Otherwise, it would be very complicated for maintenance: we will have to ask customers to change their configuration each time we want to upgrade the platform.
We therefore ask customers to delegate part of their DNS to us. This means that we will be able to configure the corresponding IP address for the delegated domain.
The process is quite simple, on Administration / Domain Management interface, click on 'Add subdomain' to add a domain name that will be delegated.\
Select A record and select how to provide the certificate:
* Use Let's Encrypt certificate: with this method, the certificate will be automatically generated. Follow the steps on the interface, no action is required on your side.
* Use your own certificate: this will require to provide the following elements:
\- The SSL certificate(s) linked to the subdomain(s) entered above\
\- The key of the certificate\
\- The chain of the certificate\
If you need assistance, please contact the Commanders Act support team.
## A record setup with Let's encrypt
Customers' DNS should be configured with A record information (ask your IT department).
Click on "Validate configuration" and this will test the DNS configuration.
Click then on "Generate certificates"
Click on "Test configuration" and the setup will be done.
## A record setup with your own certificate
Customers' DNS should be configured with A record information (ask your IT department).
Provide the requested information:\
\- The SSL certificate(s) linked to the subdomain(s) entered above\
\- The key of the certificate\
\- The chain of the certificate\
If you need assistance, please contact the Commanders Act support team.
Then click on "Validate configuration" and this will test the DNS configuration.
Test the configuration and the setup will be done.
## Activate the domain
Click on "Containers Integration", this will allow the domain to be included in the container configuration.
All Commanders Act tags will switch to first party collection.
This action will affect Consent, Deduplication, Campaign, Segment, Server Side
{% hint style="warning" %}
At this point, **WebContainers and Privacy banners** should be **regenerated and deployed.**
{% endhint %}
### What happens when I have 2 or more domains?
It prioritizes the domain of the website where the container is loaded. If no domain matches the domain of the website, the 1st in the list is used.
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