3Com 3500 - Manual (Page 395)

16
I
NTERNET
P
ROTOCOL
(IP)
To route packets using the Internet Protocol (IP), you:
■
Establish an IP routing interface
■
Decide which IP options and routing protocols you want to use
■
Enable IP routing
An IP routing interface defines the relationship between an IP virtual LAN
(VLAN) and the subnetworks in the IP network. Each routing IP VLAN
interface is associated with one VLAN that supports IP. The system has
one interface defined for each subnet that is directly connected to it.
You can also choose between two different routing models when you
establish an IP routing interface:
■
VLAN-based routing
Because bridging is faster in normal circumstances, the system first
tries to determine if it can bridge the frame before routing it.
■
Router port-based routing
The system first tries to route packets that belong to recognized
protocols, and then bridges all other packets. If the network or a
portion of the network is devoted to routing IP frames, this model
makes network traffic more efficient.
This chapter provides guidelines and other key information about how to
configure IP in your system. This chapter addresses the commands in the
ip
menu except for
multicast
and
ospf
, which other chapters in this
Command Reference Guide explain.
For information about IP multicast, see Chapter 18. For information
about Open Shortest Path First (OSPF) routing using IP, see Chapter 19.
For more information about IP routing, see the Implementation Guide for
your system.