
XYR301E Wireless Ethernet
User Manual
Page 64
April 2012
3.17
Routing Rules
When a XYR301-E receives an IP frame that is destined for an IP address on a different network, it checks if the
network address
matches the network address of one of its own interfaces (i.e. hard-wired Ethernet, or wireless
Ethernet, or WDS) and forwards the frame appropriately. However, if the IP network address does not match the
network address of any of its interfaces, the XYR301-E will forward the frame to its default gateway. In this case it is
assumed that the default gateway has a valid route to the destination.
In some cases, it is not practical to have just one default gateway (i.e. routed wireless networks with more than two
XYR301-E routers; and in some cases when WDS router interfaces are used). If more than one “next-hop router” is
required, the XYR301-E allows for up to 30
routing rules
to be configured. A routing rule specifies a destination
network (or host) IP address and the corresponding next-hop router that messages for the specified destination will be
forwarded to. It is assumed that the next-hop router (or
gateway
) will then deliver the data to the required destination
(or forward it on to another router that will).
The above network diagram illustrates a situation where routing rules may need to be configured. In this example, the
XYR301-E clients need only specify the Access Point as their default gateway (i.e. they require no routing rules be
configured). However, for the Access Point to be able to deliver traffic to LAN B and LAN C it needs to have routing
rules configured that specify the respective XYR301-E client/routers as next-hop routers (i.e. gateways) to networks B
and C. Note that devices on LAN A should specify the XYR301-E Access Point as their default gateway. An
alternative to adding routing rules to the XYR301-E in this example would be for each device on LAN A that needs to
communicate with LANs B and C to have independent routing rules specifying the XYR301-E clients at B and C as
gateways to those networks.
The routing rules for the Access Point in the above example are shown below. The first entry shows the route to LAN
B. The gateway for the route to LAN B is configured as the wireless IP address of the XYR301-E client connected to
LAN B. The destination for the route is configured as the
network
address of LAN B. Because the
host
id of the
destination IP address is 0, it specifies a network address. Consequently, any traffic received at the Access Point with
destination IP address 169.254.109.x (where x is any host id) will be forwarded to the XYR301-E at LAN B.
LAN C
Client
Router
Access Point
Bridge
LAN A
Client
Router
Client
Bridge
LAN B
192.168.0.34
192.168.109.40
192.168.102.17
192.168.0.72
192.168.0.34
192.168.0.72
192.168.0.73
192.168.0.74
Содержание XYR301E
Страница 2: ...Page ii April 2012 ...
Страница 18: ......