I
NTRODUCTION
1-8
Figure 1-1. Transparent Bridged Network
Accessing the Internet
To access the Internet, which uses TCP/IP protocols exclusively, the
Barricade must be configured to function as a router. One interface is the
port attached to a local Ethernet LAN (or directly to a host PC with an
Ethernet adapter), while the other is the ATM transport service running
on the DSL port. When the router receives an IP packet, the destination
network address is checked in the routing table. If the address is found, the
packet is forwarded to the associated interface/port. Otherwise, the packet
is dropped.
The routing table contains information on which networks are accessible
through each interface. The information can be dynamically updated using
the routing information protocol (RIP), or statically configured through
the management interface. If you use RIP, the router will exchange
information with neighboring routers to learn the best routes to remote
networks, and advertise the networks for which it can provide the best
route.
10/100Mbps Ethernet LAN
RouterRouter
ADSL
10/100Mbps Ethernet LAN