Configuring and Securing Intra-Array Communication

Intra-array communication is the means by which array members in an NLB deployment communicate.

The Internet Protocol (IP) address assigned to the network adapter on the internal network is also assigned as the intra-array address. If you have more than one ISA server in an array, a dedicated network adapter is required for intra-array communication.

Note 

With Windows Server 2003 Service Pack 1, dedicated network adapters are not required for host-to-host communication.

To configure intra-array communication, follow these steps:

1. Open the ISA Server Management console.

2. In the console tree, expand the Arrays node, expand the applicable array, expand Configuration, and then click the Servers node.

3. In the details pane, right-click your ISA server, and then select Properties.

4. Click the Communication tab.

5. Under Intra-Array Communication, type the IP address to be assigned for communication between your array members. Click OK.

   Note 

   By default, the intra-array IP address is set to the IP address assigned to the array members' network adapter on the internal network.

6. Click Apply to save your changes, and then click OK.

Configuring the CARP Load Factor

The load factor apprises the ISA Server array members of how much load (that is, how many requests) each member can handle. The default load factor is 100. The value can be configured anywhere between 1 and 2,147,483,647.

To configure the load factor, follow these steps:

1. Open the ISA Server Management console.

2. In the console tree, expand the Arrays node, expand the applicable array, expand Configuration, and then click the Servers node.

3. In the details pane, right-click your ISA server, and then select Properties.

4. Click the CARP tab.

5. Specify a value to assign as the load factor for the array member as shown in Figure 15-3, and click OK.

6. If you changed the default value in Step 4, click Apply to save your changes, and click OK.

Figure 15-3: You can change the default load factor of 100 on any array member from the CARP tab.

CARP and Scheduled Content Download Jobs

If you configured a scheduled content download job and CARP is enabled on the Local Host network, CARP distributes its downloaded content across the array for both incoming and outgoing Web requests after the array member has processed. You must disable CARP on the Local Host network if you want to make available scheduled content on all servers in an array (content is duplicated). If CARP is not disabled, it will prevent the content from being duplicated to reduce redundancy.

Note 

It is recommended that you enable CARP on the internal network if you have enabled it on the Local Host network so that the ISA server can access the cache from client requests made on the internal network.