Differences
- Subdomain: a separate hostname such as blog.example.com.
- Addon domain: an additional domain hosted in the same cPanel account.
- Alias: a domain that shows the same content as another domain.
- Redirect: sends visitors from one URL to another.
Best practices
Use separate cPanel accounts for unrelated businesses or security boundaries. Addon domains share the same account, so a compromise in one site can affect others in the same cPanel account.
DNS troubleshooting flow
- Find the authoritative nameservers first.
- Edit records only at the authoritative DNS provider.
- Check root domain, www, mail, MX, TXT, and any app-specific records.
- Watch for stale IPv6, duplicate SPF, and old mail records.
- Wait for TTL expiry before assuming a change failed.
Quick support handoff
If this article does not solve the issue, open a support ticket with the domain, service name, exact error, time the problem started, and what changed recently.
