Here is another real nice tool from Microsoft, it is portqueryui, the GUI version of port query. This toll becomes very handy in day to day operations. Using this toll also makes good understanding about ports being used by an application. If you did not download and played with portqueryui, go ahead and download it.
Some Ports need to be remembered
- Protocol: LDAP Port (TCP/UDP): 389 (TCP) Description: Lightweight Directory Access Protocol (LDAP), used by Active Directory
- Protocol: LDAP Port (TCP/UDP): 379 (TCP) Description: The Site Replication Service (SRS) uses TCP port 379.
- Port (TCP/UDP): 3268 (TCP) Description: Global catalog. The Windows 2000 Active Directory global catalog (which is really a domain controller “role”) listens on TCP port 3268. When you are troubleshooting issues that may be related to a global catalog, connect to port 3268 in LDP
- Protocol: DNS Port (TCP/UDP): 53 (TCP) Description: Domain Name System (DNS) is at the heart of all of the services and functions of Windows 2000 Active Directory and Exchange 2000 Server. You cannot underestimate the impact that a DNS issue can have on the system. Therefore, when service issues arise, it is always good to verify proper name resolution.
- Protocol: SMTP Port (TCP/UDP): 25 (TCP) Description: Simple Mail Transfer Protocol, is the foundation for all e-mail transport in Exchange 2000 and 2003. The SMTP Service (SMTPSvc) runs on top of the IIS Admin Service. Unlike Exchange 2007. Exchange 2007 has its own SMTP stack and it is not part of IIS anymore. Microsoft finally rewrote the SMTP stack.