Common Deployment Scenarios
This section presents some common deployment scenarios for Internet connectivity. The scenarios are presented in order of complexity, starting with the simplest configuration (a single Exchange server in its default configuration). The following table summarizes each of these common scenarios.
Summaries of common deployment scenarios for Internet connectivity
| Topology | Best for | Advantages | Considerations |
|---|---|---|---|
Single Exchange server in its default configuration |
Small business with a small user base |
Using the default configuration requires no additional configuration after you install Exchange. |
This topology does not offer the more robust protection of a firewall. Your Exchange server is exposed on the Internet. |
Dual-homed Exchange server |
Small business with a small user base |
Offers a secure configuration when behind a firewall. |
This topology should be used in conjunction with a firewall. Otherwise, your Exchange server is still exposed on the Internet. Consider using Internet Protocol security (IPSec) policies to filter ports on the Internet NIC. |
Using an Exchange bridgehead server behind a firewall |
Any size company |
Using a dedicated bridgehead server for Internet mail isolates Internet traffic. A firewall protects your intranet. |
Normally, a bridgehead server is deployed in larger companies. Because the server does not host mailboxes, it may be underutilized in smaller companies. |
Using an Exchange bridgehead server to send mail to a relay server on a perimeter network |
Medium to large companies with multiserver environments |
Offers the same advantages as an Exchange bridgehead server behind a firewall, but adds an extra layer of security by isolating your SMTP server from the Internet. An SMTP relay server, rather than an Exchange server handling Internet mail, is in an isolated network. Your user information is secured on your Exchange server behind a firewall. |
This topology involves more configuration and set up than the scenarios listed above. |
Note
For small companies that want a full-featured network solution that provides a unified setup for e-mail, group scheduling, fax, and database, as well as a shared Internet connectivity for an environment of up to fifty computers, Microsoft Windows Small Business Server2003 may be an appropriate solution. For more information about Small Business Server, see the Small Business Server Web site.