Cayman Systems 3220-H Guia do Utilizador descarregar pdf (Página 173)

Cayman 3220-H User’s Guide How Your Cayman 3220-H Works

December 2000 C-3

About Bridging

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.

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.

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.

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.

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

1 2 ... 168 169 170 171 172 173 174 175 176 177 178 ... 201 202

Sem comentários

Cayman Systems 3220-H Guia do Utilizador Página 173