Tcp/Ip Routing; Bridging - Cayman Systems 2E-H User Manual

About Bridging

TCP/IP Routing

Bridging

How Your Cayman 2E-H Works
C-2
When NAT is disabled, the Cayman 2E-H 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.
Your Cayman 2E-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.
As a TCP/IP router, your Cayman 2E-H keeps track of the networks
that are accessible through each network interface. If you have
configured your Cayman 2E-H to use the Routing Information
Protocol (RIP), the Cayman 2E-H exchanges information with other
routers to learn about the best routes to remote networks and to
advertise the networks for which the Cayman 2E-H is the appropriate
route.
When it receives a TCP/IP packet, the Cayman 2E-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.
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-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 2E-H uses this bridging
table to identify which hosts are accessible through which of its
network interfaces. The Cayman 2E-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
2E-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.
Cayman 2E-H User's Guide
November 2000