5.3. IPv4 DHCP Server
A NetDefendOS
DHCP Server
object assigns and manages IP addresses taken from a specified
address pool. These servers are not limited to serving a single range of IP addresses but can use
any IP address range that can be specified by a NetDefendOS IP address object.
The
DHCPServer
object is used for IPv4 addresses and the
DHCPv6Server
object is used for IPv6
objects. The two are configured in very similar ways although the underlying implementations
are very different. The IPv6 server also provides several options which do not exist for IPv4. DHCP
relay and IP pools cannot currently be used with IPv6 DHCP.
Multiple DHCP Servers
The administrator has the ability to set up one or more logical IPv4 or IPv6 DHCP servers in
NetDefendOS. Filtering of DHCP client requests to different DHCP servers is based on a
combination of the following
DHCP Server
properties:
•
Interface
Each NetDefendOS interface can have, at most, one single logical DHCP server associated
with it. In other words, NetDefendOS can provision DHCP clients using different address
ranges depending on what interface they are located on.
•
Relay Filter
The value of the
Relay Filter
property is also used to determine which
DHCP Server
object to
use. The default value of
all-nets
means that all addresses are accepted and only the interface
is considered in making a DHCP server selection. The other options for this parameter are
described further below.
Searching the Server List
Multiple DHCP servers form a list as they are defined, the last defined being at the top of the list.
When NetDefendOS searches for a DHCP server to service a request, it goes through the list from
top to bottom and chooses the first server with a matching combination of interface and relayer
IP filter value. If there is no match in the list then the request is ignored.
The DHCP server ordering in the list can, of course, be changed through one of the user
interfaces.
Setting the Relay Filter Property
As explained above, the
DHCP Server
object used for a client is selected based on a match of both
the
Interface
and
Relay Filter
properties of the object. A
DHCP Server
object must have a
Relay
Filter
value specified and the possible values are the following:
•
0.0.0.0/0
The default value is
0.0.0.0/0
(all-nets). This means all DHCP requests will match this filter
value regardless if the DHCP requests comes from a client on the local network or has arrived
via a DHCP relayer.
•
A value of 0.0.0.0
The value
0.0.0.0
will match DHCP requests that come from a local client only. DHCP requests
that have been relayed by a DHCP relayer will be ignored.
Chapter 5: DHCP Services
397
Содержание NetDefendOS
Страница 30: ...Figure 1 3 Packet Flow Schematic Part III Chapter 1 NetDefendOS Overview 30 ...
Страница 32: ...Chapter 1 NetDefendOS Overview 32 ...
Страница 144: ...Chapter 2 Management and Maintenance 144 ...
Страница 220: ... Enable DHCP passthrough Enable L2 passthrough for non IP protocols 4 Click OK Chapter 3 Fundamentals 220 ...
Страница 267: ... SourceNetwork lannet DestinationInterface any DestinationNetwork all nets 4 Click OK Chapter 3 Fundamentals 267 ...
Страница 284: ...Chapter 3 Fundamentals 284 ...
Страница 360: ...The ospf command options are fully described in the separate NetDefendOS CLI Reference Guide Chapter 4 Routing 360 ...
Страница 392: ...Chapter 4 Routing 392 ...
Страница 396: ...Web Interface 1 Go to Network Ethernet If1 2 Select Enable DHCP 3 Click OK Chapter 5 DHCP Services 396 ...
Страница 419: ... Host 2001 DB8 1 MAC 00 90 12 13 14 15 5 Click OK Chapter 5 DHCP Services 419 ...
Страница 420: ...Chapter 5 DHCP Services 420 ...
Страница 424: ...2 Now enter Name lan_Access Action Expect Interface lan Network lannet 3 Click OK Chapter 6 Security Mechanisms 424 ...
Страница 573: ...Chapter 6 Security Mechanisms 573 ...
Страница 575: ...This section describes and provides examples of configuring NAT and SAT rules Chapter 7 Address Translation 575 ...
Страница 607: ...Chapter 7 Address Translation 607 ...
Страница 666: ...Chapter 8 User Authentication 666 ...
Страница 775: ...Chapter 9 VPN 775 ...
Страница 819: ...Chapter 10 Traffic Management 819 ...
Страница 842: ...Chapter 11 High Availability 842 ...
Страница 866: ...Default Enabled Chapter 13 Advanced Settings 866 ...
Страница 879: ...Chapter 13 Advanced Settings 879 ...