Use this notebook to create or modify a subnet, its address range and excluded addresses, lease time value for those addresses, and DHCP options served to clients that are assigned addresses from the subnet.
Two of the tabs in this notebook are the DHCP Options tab and the Miscellaneous tab.
Fields and settings on the Subnet Definition tab include:
Enter the subnet mask for the subnet in dotted decimal notation or in integer format. The subnet mask defines the entire range of IP addresses in the subnet. For example, enter a subnet mask as a dotted decimal notation of 255.255.240.0 or an integer format of 20. In subnet 9.67.48.0, a mask of 255.255.240.0 implies an address range from 9.67.48.1 to 9.67.63.254. The value 20 is the total number of 1s in a mask expressed in binary as 11111111.11111111.11110000.00000000.
In dotted-decimal notation, enter the starting and ending values for a range of IP addresses to serve to clients in the subnet.
Enter IP addresses to exclude from the subnet. To prevent another client from using the fixed address of a router or nameserver, enter the IP address in dotted decimal notation and click Add. For example, exclude hosts that manually define their IP address.
You can enter a single address to exclude or a range of addresses to exclude. To remove an address from the exclusion list, click the address and click Remove. You cannot remove an address that is already excluded from the parent subnet.
Note:
It is recommended that each range of excluded addresses not contain more than 10 addresses. Each excluded address results in a separate Client statement in the configuration file. To exclude larger numbers of addresses, define subnets that do not include the addresses to be excluded. For example, to exclude addresses 50-75 in subnet 9.67.3.0, specify:balance subnet 9.67.3.0 255.255.240.0 9.67.3.1-9.67.3.49 label:WIRE1/1 subnet 9.67.3.0 255.255.240.0 9.67.3.76-9.67.3.100 label:WIRE1/2