In one of my customers I faced a very strange issue during the installation of an Enterprise Root Certificate Authority. This type of CA is important for an enterprise company with properly working Active Directory infrastructure, becuase in this case the AD itself is managing the certificate enrollment/revocation tasks, which is very important from management and operation perspective.
However the installation of this certificate authority is not so complex, many prerequisites must be done before the installation happens. Especially, if the domain controller(s) and the CA server are on different locations separated with firewall.
The most important requirements:
Protocol |
Port |
From |
To |
Action |
Kerberos |
TCP/464 |
Certificate Enrollment Web Services |
Domain Controllers (DC) |
Allow |
LDAP |
TCP/389 and UDP/389 |
Certificate Enrollment Web Services |
Domain Controllers (DC) |
Allow |
LDAP |
TCP/636 |
Certificate Enrollment Web Services |
Domain Controllers (DC) |
Allow |
DCOM/RPC |
Random port above port 1023 |
Certificate Enrollment Web Services All XP clients requesting certs |
CA |
Allow |
HTTPS |
TCP/443 |
All clients requesting certs |
Certificate Enrollment Web Services |
Allow |
GC |
TCP/3268 |
CA server |
Domain Controller |
Allow |