D-Link NetDefend DFL-210 User Manual page 180

4.7.1. Overview
Chapter 4. Routing
routing table will be connected together by NetDefendOS and no matter how interfaces are
associated with the switch routes, transparency will exist between them.
For example, if the interfaces if1 to if6 appear in a switch routes in routing table A, the resulting
interconnections will be as illustrated below.
Connecting together switch routes in this way only applies, however, if all interfaces are associated
with the same routing table. The situation where they are not, is described next.
Creating Separate Transparent Mode Networks
If we now have two routing tables A and B so that interfaces if1, if2 and if3 appear in a switch route
in table A and interfaces if4, if5, if6 appear in a switch route in table B, the resulting interconnections
will be as illustrated below.
The diagram above illustrates how switch route interconnections for one routing table are
completely separate from the switch route interconnections for another routing table. By using
different routing tables in this way we can create two separate transparent mode networks.
The routing table used for an interface is decided by the Routing Table Membership parameter for
each interface. To implement separate Transparent Mode networks, interfaces must have their
Routing Table Membership reset.
By default, all interfaces have Routing Table Membership set to be all routing tables. By default,
one main routing table always exists and once an additional routing table has been defined, the
Membership for any interface can then be set to be that new table.
Transparent Mode with VLANs
If transparent mode is being set up for all hosts and users on a VLAN then the technique described
above of using multiple routing tables also applies. A dedicated routing table should be defined for
each VLAN ID and switch routes should then be defined in that routing table which refer to the
VLAN interfaces. The reason for doing this is to restrict the ARP requests to the interfaces on which
the VLAN is defined.
To better explain this, let us consider a VLAN vlan5 which is defined on two physical interfaces
called if1 and if2. Both physical interfaces have switch routes defined so they operate in transparent
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