NT Server Roles
- PDC - Domain administration can only be done by the primary domain controller. The BDC can be used to update the SAM on the PDC. If the PDC is down, this cannot be done.
- BDC - Backup domain controller is used to keep copies of the domain database and authenticate users. The nearest BDC is normally used to authenticate a user.
- Member Server - A server (included in the domain) that is not a domain controller. The user must be logged onto the domain to use this server. A member server can be moved between domains since it does not have a domain SID. Types of servers are:
- Application Server - Does the server part or back end of a client server application. An application server is SQL server. Microsoft access would be the front end (client side) to an SQL server which will return data based on users' requests.
- Internet Servers - IIS comes with NT server 4. Suppotrs HTTP, FTP, and gopher. Place a firewall between this server and your network.
- Messaging Servers - Microsoft Exchange or Lotus Notes. Can be used for paging, or sorting through internet and bulletin board articles.
- Gateway - GSNW (Gateway services for NetWare). RAS servers are considered a serial to network gateway. They can poll news sources and make information indirectly available to clients.
Computers that are PDCs or BDCs cannot move between domains since each domain has a domain ID assigned when the first domain controller is created. Also the domain controllers have a different directory structure than member servers. The "Server Manager for Domains" is used to promote a BDC to PDC. This causes the PDC to change to a BDC.
Typical Server Hardware
|Server Type||Processor||RAM||Hard Drive||Backup||Network Adapter||CD-ROM||Other|
|File Server||PI 150Mhz||48M||8G||DAT 4G||100Mhz ethernet||4X CD-ROMs(2)|
|Application Server||Dual PII 266Mhz||128M||5G||Worm Near-line||100Mhz ethernet with adapter for each subnet||2X CD-ROM|
|Internet Server||PI 100Mhz||32M||2G||QIC 2G||Ethernet||4X CD-ROM||T-1 interface|
|Messaging Server||PI 200Mhz||32M||2G||QIC 2G||Ethernet||4X CD-ROM||Two fast modems|
|RAS Server||PI 100Mhz||32M||1G||None||Ethernet||2X CD-ROM||Multiport serial board with modems|
|Firewall||PI 150Mhz||32M||1G||None||Dual ethernet||2X CD-ROM|
NT Workstation 4.0 can only have 10 inbound IP connections at the same time with unlimited outbound connections. NTWS 3.51 does not have this limitation and can be used as a firewall.
Important file Server Characteristics
- Security - Includes fault tolerance, recovery, network security, and file system security.
- Capacity - Requirements are 300Mb + (OS network load factor) times (50Mb per client).
- Speed - Large RAM caches are used to improve speed along with disk striping and RAID hardware.