Choose an SSL certificate based on the number of domains you need to bind

Certificates can support binding to a single domain name (or IP), multiple domain names (or IPs), and they also allow using one certificate for the main site and all its sub-sites. Confirm the number of sites that require encrypted connections, collect the domain names, and further determine the required certificate type according to the following categories.

Domain Type	Description
Single-Domain SSL	A certificate that can only protect one primary domain name or one subdomain, or one public IP address.
Multi-Domain SSL	A certificate that can protect multiple different domain names by default (no restriction on whether they are first-level, second-level, or third-level domain names). After the certificate is issued, you can add more domain names to be protected on the basis of the originally protected domain names for an additional fee. Most multi-domain certificates support binding up to 250 domain names by default.
Wildcard SSL	Used to protect one primary domain name and all its subdomains at the same level. This is achieved by using an asterisk * as a wildcard in the domain name. For example, *.racent.com can protect racent.com and all its subdomains (next-level domains) such as www.racent.com, mail.racent.com, etc., but it does not support cross-level subdomains such as aaa.mail.racent.com….

Instructions

• Adding or removing domain names for a multi-domain certificate may require reissuance of the certificate; all included domain names share the same expiration date.
• A single certificate can also bind mixed domain types at the same time. For example, a single domain and a wildcard domain can be bound in the same certificate.
• Some certificates support mixed binding of IP addresses and domain names.