Advanced IP Pool Options
Advanced options available for IP Pool configuration are:
Routing Table
The routing table to be used for lookups when resolving the
destination interfaces for the configured DHCP servers.
Receive Interface
A "simulated" virtual DHCP server receiving interface. This setting is
used to simulate a receiving interface when an IP pool is obtaining IP
addresses from internal DHCP servers. This is needed since the
filtering criteria of a DHCP server includes a Receive Interface.
An internal DHCP server cannot receive requests from the IP pool
subsystem on an interface since both the server and the pool are
internal to NetDefendOS. This setting allows such requests from a
pool to appear as though they come from a particular interface so
that the relevant DHCP server will respond.
MAC Range
A range of MAC addresses that will be used to create "fake" DHCP
clients. Used when the DHCP server(s) map clients by the MAC
address. An indication of the need for MAC ranges is when the DHCP
server keeps giving out the same IP for each client.
Prefetch leases
Specifies the number of leases to keep prefetched. Prefetching will
improve performance since there will not be any wait time when a
system requests an IP (while there exists prefetched IPs).
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.
Sender IP
This is the source IP to use when communicating with the DHCP
server.
Memory Allocation for 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 judgment as to the optimal initial
size of the prefetch cache.
Listing IP Pool Status
The CLI command
ippools
can be used to look at the current status of an IP pool. The simplest
form of the command is:
gw-world:/> ippool -show
Chapter 5: DHCP Services
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Summary of Contents for NetDefendOS
Page 30: ...Figure 1 3 Packet Flow Schematic Part III Chapter 1 NetDefendOS Overview 30 ...
Page 32: ...Chapter 1 NetDefendOS Overview 32 ...
Page 144: ...Chapter 2 Management and Maintenance 144 ...
Page 284: ...Chapter 3 Fundamentals 284 ...
Page 392: ...Chapter 4 Routing 392 ...
Page 419: ... Host 2001 DB8 1 MAC 00 90 12 13 14 15 5 Click OK Chapter 5 DHCP Services 419 ...
Page 420: ...Chapter 5 DHCP Services 420 ...
Page 573: ...Chapter 6 Security Mechanisms 573 ...
Page 607: ...Chapter 7 Address Translation 607 ...
Page 666: ...Chapter 8 User Authentication 666 ...
Page 775: ...Chapter 9 VPN 775 ...
Page 819: ...Chapter 10 Traffic Management 819 ...
Page 842: ...Chapter 11 High Availability 842 ...
Page 866: ...Default Enabled Chapter 13 Advanced Settings 866 ...
Page 879: ...Chapter 13 Advanced Settings 879 ...