Bridging/Routing Models 3-7
In the LANplex bridging/routing model, a packet is routed as follows (see
Figure 3-7):
1The packet enters the module.
2The packet’s destination address is examined by the bridging layer.
3The destination address corresponds to the address of one of the module
ports configured for routing (as opposed to a learned end-station address).
The packet is passed to the router interface associated with the port on
which the packet was received.
4The routing layer:
aSelects a destination interface based on the destination network
address.
bDetermines the MAC address of the next hop (either the destination
host or another gateway).
cPasses the packet back to the bridging layer.
5The bridging layer then selects a segment (port) based on the destination
MAC address and forwards the packet to that segment.
Figure 3-7 Routing in the LANplex Bridging/Routing Model
1
Transmitting Host
3
Destination Host
5
2
123
Router Interfaces
Bridging Layer
Routing Layer
Subnets
4
123
Router
Bridge