Chapter Three
Operation
Page 37 November
2008
A consequence of using a different network address for the WDS link between unit A and B is that
we now need to configure a
routing rule
at units A and B so that the D2 W MDME 2400 can
determine where to send traffic destined for the respective network addresses of A and B. For
example, if unit B receives traffic destined for network 192.168.0.x (i.e. somewhere on unit A’s
network), the routing rule specifies that the traffic must be forwarded to the end-point of the WDS
link to unit A. The routing rules for unit B are shown below (for more information on routing rules,
refer to Section 3.11, “Routing Rules”).
The second WDS entry above specifies the WDS link to unit C as a WDS router interface with IP
address 169.254.5.3. As with the WDS link to unit A, we use a different IP network address than
the default interface (note that this network address 169.254.5.x is also different to that used for the
WDS link to unit A 169.254.0.x, so that these separate WDS interfaces are not internally bridged).
Also, as with the WDS link to unit A, a routing rule is added to direct traffic destined for the
network address of unit C (192.168.6.x). So, in this example, unit B has a total of three (3) IP
addresses: 192.168.5.3 for the default interface; 169.254.0.3 for the WDS link to unit A; and
169.254.5.3 for the WDS link to unit C.
Note that we choose to always use the same host
address of 3 for unit B on all of its interfaces regardless of the network address.
The third WDS entry above specifies the WDS link to unit D. In the example, unit D has the same
network address as unit B; therefore, we wish to have the WDS interface link to unit D bridged with
the default interface. Because we don’t specify a router IP address for the third entry, the D2 W
MDME 2400 automatically bridges this interface with the default wireless interface.
The routing rules for unit B are shown above. The routing rule for directing traffic to unit A can be
seen to specify 192.168.0.0 as the destination address (the
network
address of unit A) – because the
last byte is zero, this refers to a route to the
network
192.168.0.x (as opposed to a route to an
individual
host
). The same rule specifies the address 169.254.0.2 as the gateway address (this is the
WDS Router IP address that unit A has been configured with for its WDS link to unit B). So, this
routing rule effectively tells the D2 W MDME 2400 that any traffic destined for the network
192.168.0.x should be forwarded to unit A via the WDS link. Units A and C would also require
similar pairs of routing rules to direct traffic to the network addresses at the end points of their
respective WDS links. For unit D, it would suffice to simply configure unit B as its default
gateway, as unit B would then forward on any traffic destined for units A and C. Refer to Section
3.11, “Routing Rules,” for further information.
