This document explains how to load balance ISA server by configuring NLB on the external NIC on ISA server. Also it explains publishing multiple web sites using server publishing and how it works with NLB. Objective: To configure ISA server for load balancing and fault tolerance using Network Load Balancing service. Lab Setup: Lab has one web server hosting two applications: and using different IP addresses:
TCP/IP Settings on Web ServerConfigure web server as SecureNAT client by specifying the internal IP of ISA server as gateway address
There are 2 ISA servers connected to external network segment and on internal side to web server through a hub.(see nlb.vsd ) TCP/IP settings on external NIC:
TCP/IP settings on internal NIC:
ISA Servers Configuration1.Configure NLB on ISA:
Note: If the host priority is same on both servers, NLB will fail. You can do configuration for remote management and port rules according to organization requirements. Those configurations are not explained in this document. 2. Server Publishing Configuration: a. Create Protocol Definition for HTTP(IN) and HTTPS(IN) a. Right click on Protocol Definitions-> New-> Definition
This will start the New Protocol definition wizard. b. Specify the definition name and click on Next
c. Specify the Port Number, Protocol Type and Direction and click Next
d. Specify if you want secondary connections and click Next
e. Click on Finish to finish the protocol definition wizard
b. Define Protocol Rules a. Right click on Protocol rule and select New Rule
b. Specify the name for the rule and click Next
c. Select the desired option and click Next
d. Under “Apply This rule to” box select “selected protocol“ e. And under Protocol box, select the protocol you defined earlier and click Next
e. Select the schedule for the rule to apply and click Next
f. Select the desired option and click Next
g. Click on Finish
c. Create Server Publishing Rule a. Right Click on Server Publishing Rules and click New Rule
b. Specify the name for the rule and click Next
c. Specify the IP address of internal Server you want to publish and external IP address of ISA server (this should be the Virtual IP address used for load balancing) and click Next
d. Specify the protocol rule you defined earlier and click Next
e. Select the desired option and click Next
f. Click on Finish
3. Configuring DNS a. Create the entry for the web site to resolve to cluster primary IP address. (I used the local host file on the client ). Configuring Second Host In The Cluster (second ISA Server)
Publishing Mutliple Web Sites: To publish multiple web sites using server publishing requires additional IP address. Remember you can publish a particular service only once per IP address (Tom’s Book Page no. 654). To host multiple Web sites with different IP addresses on a Network Load Balancing cluster you need to enter additional virtual IP addresses in the Advanced TCP/IP Settings dialog box, not in the Network Load Balancing Properties dialog box.
Follow the server publishing steps to publish second web site using the second primary cluster IP on ISA |