Microsoft 2004 User Manual

ISA Server 2004 Configuration Guide 245 

Create the Network Rule at the Main Office 

The ISA Server 2004 firewall must know what method to use to route packets to the branch 
office network. There are two options: Route and NAT. A route relationship routes packets to 
the branch office and preserves the source IP address of the clients who make a connection 
over the site-to-site link. A NAT relationship replaces the source IP address of the client 
making the connection. In general, the route relationship provides a higher level of protocol 
support, but the NAT relationship provides a higher level of security. 

Perform the following steps to create a Network Rule that controls the routing relationship 
between the main office and branch office networks: 

1. Expand 

the 

Configuration node in the left Pane of the console. Click on the Networks 

node. 

2.  Click on the Network Rules tab in the Details Pane. Click on the Tasks tab in the Task 

Pane. Click Create a New Network Rule. 

3. On 

the 

Welcome to the New Network Rule Wizard page, enter a name for the rule in 

the Network rule name text box. In this example, we call the rule MainBranch. Click 
Next. 

4. On 

the 

Network Traffic Sources page, click Add. 

5. In 

the 

Add Network Entities dialog box, click the Networks folder. Double click on the 

Internal network. Click Close. 

6. Click 

Next on the Network Traffic Sources page. 

7. On 

the 

Network Traffic Destinations page, click Add. 

8. In 

the 

Add Network Entities dialog box, double click on the Branch network. Click 

Close. 

9. Click 

Next on the Network Traffic Destinations page. 

10. On the Network Relationship page, select Route.