D-Link 800 - DFL 800 - Security Appliance, User Manual

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Maximum free The maximum number of "free" IPs to be kept. Must be equal to or
greater than the prefetch parameter. The pool will start releasing (giving
back IPs to the DHCP server) when the number of free clients exceeds
this value.
Maximum clients Optional setting used to specify the maximum number of clients (IPs)
allowed in the pool.
Using Prefetched Leases
As mentioned in the previous section, the Prefetched Leases option specifies the size of the cache of
leases which is maintained by NetDefendOS. This cache provides fast lease allocation and can
improve overall system performance. It should be noted however that the entire prefetched number
of leases is requested at system startup and if this number is too large then this can degrade initial
performance.
As leases in the prefetch cache are allocated, requests are made to DHCP servers so that the cache is
always full. The administrator therefore has to make a judgement as to the optimal initial size of the
prefetch cache.
Example 5.5. Creating an IP Pool
This example shows the creation of an IP Pool object that will use the DHCP server on IP address 28.10.14.1 with
10 prefetched leases. It is assumed that this IP address is already defined in the address book as an IP object
called ippool_dhcp
CLI
gw-world:/> add IPPool ip_pool_1 DHCPServerType=ServerIP ServerIP=ippool_dhcp
Web Interface
1. Go to Objects > IP Pools > Add > IP Pool
2. Now enter Name: ip_pool_1
3. Select Specify DHCP Server Address
4. Add ippool_dhcp to the Selected list
5. Select the Advanced tab
6. Set Prefetched Leases to 10
7. Click OK
5.5. IP Pools Chapter 5. DHCP Services
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