Each Acquia Cloud application has a single public IP address. This is true even if it is an Acquia Cloud Enterprise application is hosted on a high-availability hosting cluster of several web servers. This address points to a load balancer that detects incoming connections to your application and spreads them among the cluster of web servers.
For your application to be available on the Internet, incoming connections must go to the Acquia Cloud load balancer. You can enable this through your DNS provider by pointing your domain name's A Records entry to the public IP address. In your DNS provider's web interface, change the A Records entry for your domain name to point to the public IP address, which is listed on the Domain page of the Acquia Cloud interface. For example, suppose your application's domain name is
www.example.com and your public IP address is 126.96.36.199. Set the A Records entry for
www.example.com to 188.8.131.52.
Do not set your domain name's CNAME entry to an
acquia-sites.com domain. Doing so can make your application load more slowly, and can cause unpredictable results or even downtime, especially if configuration changes are being made or tested to the load balancers. In addition, DNS service is not included in Acquia's uptime guarantee. This means that if the Acquia DNS provider has an outage, requests to
*.prod.acquia-sites.com would fail to resolve, and any domains that are pointed to the Acquia domain (rather than to a public IP address or an Elastic Load Balancer) would fail.
DNS settings with an Elastic Load Balancer
If you have an Elastic Load Balancer (ELB) for your application (which would be the case if you have enabled a legacy SSL certificate for your application), instead of changing the A Records entry, change the CNAME entry for your domain name. In your DNS provider's web interface, change the CNAME entry for your domain name to point to the URL of your Acquia Cloud environment, which will be the URL of your Elastic Load Balancer and which is listed on the Acquia Cloud interface Domains page for the environment. Don't use a DNS A Record to point to the underlying IP address of the ELB, since the IP address may change from time to time.
For example, suppose your application's domain name is
www.example.com and your Production environment's URL is
ab-1234-us-east-1.elb.amazonaws.com. Set the CNAME entry for
Acquia may require verification of your DNS TXT record. If that is the case, the verification will be sent with a hash value.
Using an Elastic IP address
An Acquia Cloud application can use an Elastic IP Address (EIPs) in order to have a static IP address assigned to its server instance. Without an Elastic IP, your instances' IP addresses are subject to change at any time as the underlying hardware is relaunched or replaced. For most purposes, that doesn't make a difference for Acquia Cloud applications. However, you might want to use EIPs if it is important to you to maintain the same IP address, for example, so that you can add them to a whitelist, integrate them with a Single-Sign-On (SSO) solution, or use a third-party service that requires a static IP address.
An EIP persists when a server is relaunched or rebooted. It will be lost if a server is suspended, for example after being removed due to a downsize.
Using EIPs can reduce your flexibility if you need additional server capacity to meet increased application traffic. While the Acquia Operations team can quickly provision new instances for your application in response to demand, the additional instances can't be brought into service until the new EIPs associated with them can be added to your whitelist or other system.
Changes to IP address
If you have an existing application hosted on Acquia Cloud Enterprise and you move it to Acquia Cloud Shield with VPN, your IP address will change. This includes any elastic IP addresses (EIPs). IP addresses cannot be moved into or out of a VPC.
As a result, when you set up your application in Acquia Cloud Shield with VPN, you need to point the DNS records of your application to the new IP address within the VPC. See Acquia Cloud Shield.