Configuring subnet option sets

You can add subnets configured on your network that have DHCP clients. For existing subnet entries, you can change the address pool, default lease parameters and DHCP options. You can also access the Address Allocation Server from the Subnet Entry screen and modify address pools to facilitate the changes you need to make. If you need to change a subnet address, you must first delete the subnet entry and then define it again with the new subnet address.

Adding a subnet option set

To add a subnet definition using the DHCP Server Manager:

1. Select View Subnets.

2. Select Entry Add.

3. Enter the subnet's IP address in dot notation, the subnet mask, the address pool assigned to the subnet and an optional description.

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   NOTE: To define or modify an address pool, click on Address pools to invoke the Address Allocation Manager.

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4. Click on Lease to enter the default lease parameters:

   Default lease time

   To set an infinite default lease, click on Unlimited. Otherwise, click on Limited and enter the lease in days, hours and minutes. The lease must be greater than 0, and less than or equal to 49,674 days (approximately 136 years).

   Maximum lease time

   To set an infinite maximum lease, click on Unlimited. Otherwise, click on Limited and enter the maximum lease in days, hours and minutes. The lease must be greater than 0, and less than or equal to 49,674 days.

   Renewal on (percent)

   Enter the lease renewal time as a percentage of the lease. The default value is 75% of the lease, suggesting the client request a renewal when the lease is three-quarters over.

   Rebind on (percent)

   Enter the lease rebind time as a percentage of the lease. The rebind time defines when a client makes a second attempt to renew its lease if the first attempt failed. The default is 90% of the lease, suggesting the client make a second attempt to renew the lease when 10% of the lease remains.

5. To configure DHCP options that are specific to the subnet you are adding, click on Generic. See ``Configuring DHCP options'' for more information.

6. Click on OK.

Modifying a subnet option set

To modify a subnet definition using the DHCP Server Manager:

1. Select View Subnets.

2. Highlight the subnet you want to change and select Entry Modify.

3. Make the necessary changes and click on OK.

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   NOTE: You cannot change the subnet address.

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Deleting a subnet option set

To delete a subnet definition using the DHCP Server Manager:

1. Select View Subnets.

2. Highlight the subnet you want to delete.

3. Select Entry Delete.

4. When asked to confirm that you want to delete the subnet, click on OK.