ARP queries. ARP works because the clients and the NetDefendOS interface are part of the same
network.
A second network might then be added to the same physical interface via a switch, but with a
new network range that does not include the physical interface's IP address. This network is said
to be
not bound
to the physical interface. Clients on this second network will not then be able to
communicate with the NetDefend Firewall because ARP will not function between the clients
and the interface.
To solve this problem, a new route is added to NetDefendOS with the following parameters:
•
Interface: The interface on which the second network is found.
•
Network: The IP address range of the second network.
•
Local IP Address: An address within the second network's IP range.
When the
Default Gateway
of the second network's clients is now set to the same value as the
Local IP Address
of the above route, the clients will be able to communicate successfully with the
interface. The IP address chosen in the second network is not significant, as long as it is the same
value for the
Default Gateway
of the clients and the
Local IP Address
.
The effect of adding the route with the
Local IP Address
is that the firewall will act as a gateway
with the
Local IP Address
and respond to, as well as send out, ARP queries as though the interface
had that IP address.
The diagram below illustrates a scenario where this feature could be used. The network
10.1.1.0/24
is bound to a physical interface that has an IP address within the network of
10.1.1.1
. If
we now attach a second network
10.2.2.0/24
to the interface via the switch, it is unbound since
the interface's IP address does not belong to it.
Figure 4.2. Using Local IP Address with an Unbound Network
By adding a NetDefendOS route for this second network with the
Local IP Address
specified as
10.2.2.1
, the interface will then respond to ARP requests from the
10.2.2.0/24
network. The clients
Chapter 4: Routing
289
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 ...