Netopia 2e-w Guia Do Utilizador
How Your Cayman 2E-W Works
Cayman 2E-W User’s Guide
C-2
November 2000
communicating through an Internet service provider typically
enable NAT, since they often receive one IP address from the ISP.
enable NAT, since they often receive one IP address from the ISP.
When NAT is disabled, the Cayman 2E-W acts as a traditional TCP/IP
router. It uses RIP (Routing Information Protocol) to advertise the
networks connected to its Ethernet ports to the routers on the other
end of the network connection.
router. It uses RIP (Routing Information Protocol) to advertise the
networks connected to its Ethernet ports to the routers on the other
end of the network connection.
About Bridging
Your Cayman 2E-W device functions as a network router for TCP/IP
traffic and as a network bridge for other traffic, such as NetWare,
DECnet, or AppleTalk.
traffic and as a network bridge for other traffic, such as NetWare,
DECnet, or AppleTalk.
TCP/IP Routing
As a TCP/IP router, your Cayman 2E-W keeps track of the networks
that are accessible through each network interface. If you have
configured your Cayman 2E-W to use the Routing Information
Protocol (RIP), the Cayman 2E-W exchanges information with other
routers to learn about the best routes to remote networks and to
advertise the networks for which the Cayman 2E-W is the
appropriate route.
that are accessible through each network interface. If you have
configured your Cayman 2E-W to use the Routing Information
Protocol (RIP), the Cayman 2E-W exchanges information with other
routers to learn about the best routes to remote networks and to
advertise the networks for which the Cayman 2E-W is the
appropriate route.
When it receives a TCP/IP packet, the Cayman 2E-W looks up the
network portion of the packet's destination IP address in its routing
table, and then forwards the packet through the network interface
that will let the packet reach its destination most efficiently.
network portion of the packet's destination IP address in its routing
table, and then forwards the packet through the network interface
that will let the packet reach its destination most efficiently.
Bridging
Bridges let you join two local area networks, so that they appear to
be part of the same physical network. As a bridge for protocols other
than TCP/IP, your Cayman 2E-W keeps track of as many as 255 MAC
(Ethernet hardware) addresses, each of which uniquely identifies an
individual host on a network. Your Cayman 2E-W uses this bridging
table to identify which hosts are accessible through which of its
network interfaces. The Cayman 2E-W builds its bridging table by
storing the MAC address of each packet it sees, along with the
interface over which it received the packet. Over time, the Cayman
2E-W learns which hosts are available through its Ethernet A port,
be part of the same physical network. As a bridge for protocols other
than TCP/IP, your Cayman 2E-W keeps track of as many as 255 MAC
(Ethernet hardware) addresses, each of which uniquely identifies an
individual host on a network. Your Cayman 2E-W uses this bridging
table to identify which hosts are accessible through which of its
network interfaces. The Cayman 2E-W builds its bridging table by
storing the MAC address of each packet it sees, along with the
interface over which it received the packet. Over time, the Cayman
2E-W learns which hosts are available through its Ethernet A port,