Руководство Пользователя для Netopia 3220-h
Cayman 3220-H User’s Guide
How Your Cayman 3220-H Works
December 2000
C-3
About Bridging
and Routing
and Routing
Your Cayman 3220-H 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 3220-H keeps track of the networks
that are accessible through each network interface. If you have
configured your Cayman 3220-H to use the Routing Information
Protocol (RIP), the Cayman 3220-H exchanges information with
other routers to learn about the best routes to remote networks and
to advertise the networks for which the Cayman 3220-H is the
appropriate route.
that are accessible through each network interface. If you have
configured your Cayman 3220-H to use the Routing Information
Protocol (RIP), the Cayman 3220-H exchanges information with
other routers to learn about the best routes to remote networks and
to advertise the networks for which the Cayman 3220-H is the
appropriate route.
When it receives a TCP/IP packet, the Cayman 3220-H 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 3220-H keeps track of as many as 255 MAC
(Ethernet hardware) addresses, each of which uniquely identifies an
individual host on a network. Your Cayman 3220-H uses this bridging
table to identify which hosts are accessible through which of its
network interfaces. The Cayman 3220-H 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
3220-H learns which hosts are available through its Ethernet A port,
which hosts are available through its Ethernet B port, and which
hosts are available through its serial port.
be part of the same physical network. As a bridge for protocols other
than TCP/IP, your Cayman 3220-H keeps track of as many as 255 MAC
(Ethernet hardware) addresses, each of which uniquely identifies an
individual host on a network. Your Cayman 3220-H uses this bridging
table to identify which hosts are accessible through which of its
network interfaces. The Cayman 3220-H 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
3220-H learns which hosts are available through its Ethernet A port,
which hosts are available through its Ethernet B port, and which
hosts are available through its serial port.
When the Cayman 3220-H receives a packet, it looks up the packet's
MAC address in its bridging table. If the packet is addressed to a MAC
address in its bridging table, the Cayman 3220-H forwards the packet
on the appropriate network interface. (If the appropriate interface is
the one over which the packet was received, the Cayman 3220-H
ignores it, since no action would be required.) If the packet is
MAC address in its bridging table. If the packet is addressed to a MAC
address in its bridging table, the Cayman 3220-H forwards the packet
on the appropriate network interface. (If the appropriate interface is
the one over which the packet was received, the Cayman 3220-H
ignores it, since no action would be required.) If the packet is