User guide

Chapter 5
Physical and Layer 2 Interfaces
This Chapter
This chapter introduces the physical and logical interfaces available on the base
unit router and the optional interfaces available as expansion options for the
PIC bay. Topics covered are:
■ “Interfaces” on page 73
■ “Naming Interfaces” on page 73
■ “Ethernet Ports” on page 74
■ “Asynchronous Port” on page 75
■ “ADSL and ATM (models with ADSL port)” on page 76
■ “Switch Ports” on page 77
■ “Virtual LANs” on page 80
■ “Point to Point Protocol (PPP)” on page 81
■ “Frame Relay (models with PIC bay)” on page 82
■ “Integrated Services Digital Network (ISDN) (models with PIC bay)” on page 85
■ “Configuring ISDN (models with PIC bay)” on page 87
■ “Installing Port Interface Cards (PICs) (models with PIC bay)” on page 94
■ “Connecting to a Leased Line Circuit (models with PIC bay)” on page 94
■ “Using Trace Route for IP Traffic” on page 96
Once you have configured the Layer 2 interfaces, you can configure a Layer 3
protocol to route traffic between these interfaces. A simple network overview
showing the relationship between physical interfaces (except for ADSL), data
link protocols, and network routing protocols is shown in Figure 11 on page 72.
The relationship for ADSL on router models with an ADSL port is shown in
Figure 12 on page 72.